I'm new to your channel and I'm part of the 99% of people that don't have a lot of money but can put together a fast small block to run around the streets with out of a junkyard. Love the videos. Keep up with the educational videos.
You are absolutely one of the few people that I have heard make such an intelligent statement about higher compression and boost. Apparently very few people are aware of this. I keep trying to tell people this oh, that you do not need to have 7 to 1 compression to run boost. There are actually people who run 14 to 1 compression and then boost. Regardless the reason it is going to have a snap your response is because it will still have the immediate torque. We don't have to wait for the turbo to spool up, which means you can go with a bigger Turbo for higher-end power but still have power in the low end. This also means that you don't have to overwork the turbo as much. I am currently finishing up a forged 384 Stroker with a 10.5:1 CR NA, & with only 10 PSI from the twin turbos, i am over 820 ft lb torque/ 715 HP. Those turbos are barely breaking a sweat.
Diesels on 18-wheelers use 18:1 compression ratio plus a turbo, but for different reasons. That being said, it comes down to heat management. The vulnerable parts are exhaust valves, the exhaust side of the piston, and the turbo exhaust temps.
Maybe some people worry about the ol David that is pre detonation.... But with E-85 pretty much everywhere with it's higher resistance to engine knock and its characteristic cooler burning flame... you can have your cake and eat it too. So long as you set your fuel system up to use it. But really... if you're ready to swap heads and possibly engine swap all together... doing a fuel system along with it isn't really much to add on
Great video. I have 862’s that are in mint condition that came out of a very low mileage 5.3. And I have a set of 799’s that came out of a torched 5.3. 799’s will need all work done to them. People keep telling me to run the 799’s and I’m like nope, 862’s are what I’m going to run.
I blew my lq4 up and found a lq9 block cheap and when I got the block it needed to be bored so I went .030 with +6 cc flat top pistons and the block was decked .010 and heads shaved .010 asa hot cam with 873 iron heads. I really like your info video
Before I had an ls I thought the car heads / later truck heads were what I needed until I started looking at the combustion chamber sizes. Everyone said to get the 799 heads off a late model 5.3 but with an 04 5.3 I’d be going up in cc’s and down in compression. Being that I’m not using a turbo I decided to listen to mr holdner where he shows the 706 / 862 heads make the most power so I got some junk yard heads, cleaned them, lapped the valves, and put some el cheapo eBay springs on them, then I picked up a Chinese 615-183 intake for $65 brand new, ls7 lifters, summit Vortec towing cam and it’s a totally different truck
Pretty comprehensive and to the point. Thanks. I'll have to bookmark this vid. I've always preferred a smaller CC for quicker burn, better thermal efficiency. Its all aluminum after all, it can dissipate the heat much better than cast iron, therefore these engines can take the spark advance booster so sought after, w/o pre-detonation. Would like to see them design a head w/ more dedicated cooling to help the overall thermal efficiency.
I just read an article a few weeks ago that said the 706 heads were a game changer on the LQ4. I hopped on Facebook and found a pair of them about an hour away for $50. Thanks for confirming what I was crossing my fingers for! Subscribed!
Ha! That's awesome! My LQ4 had the 873 heads on it. This build is just going to be for fun on the street. I'm going to put it on the track and see what it will do, but going to build a more serious engine for next year. I bought my car as a roller. It came off of the track running in the 8's at 160+ mph with a twin turbo 5.3. It was somewhere in the neighborhood of 1200hp. I'd like to get it back to doing that someday!
Just discovered your channel,very good information on the heads !!Loved the printed specs and the flow numbers!!Great on what heads came in which vehicles too.Look forward to seeing all you videos 👍👍
I have a 5.3 with 862 heads and a LQ4. I was thinking the same as you... LQ4 shortblock with the 862 heads, maybe smooth out the ports by hand, add a cam, and go party. I heard an engineer from Texas Speed said that he’d give up port CFM for compression any day of the week, and it makes sense. Compression will increase power everywhere.
Back in the 70's and 80's the SAE did a bunch of studies because they dropped compression into the toliet to deal with unleaded gas. Compression was the single largest factor in power and efficiency, and power rose faster than knock with compression, both static and dynamic. Power also fell off faster than knock.
Yep, I agree, with my running LQ9 (all original) I am going to simply freshen it up, (check oil pickup tube seal) and slap it in . Run it, see how I like it, then I can play with cams and what have you. Good education thanks.
@@FilthyPancakes Frankly, it didn't. I ended up tearing the engine down and could hardly get the cam out, although lifters and lobes look good. Fair amount of black carbon, but no sludge or metal, tested, and had 165 to 180 PSI in all 8 cyls dry prior. Still had crosshatch on walls and pulled one rod bearing looked good. So, now I am taking in to shop, have them do inspection and install stage two cam / bearings. put it back together and hopefully run it. Fingers crossed, potential for change without notice! LOL
I agree with host about 862s but some are more volume in combustion chamber than 61cc. Some are much more like 64.5cc so do check their chamber volume or you may be disappointed if you looking for bolt on compression increase. The higher volume chamber heads are for CA nox reduction, just a theory.
Peter Fraumeni It’s true that the chambers can vary in size, but that goes for any head. They could also be smaller as well; like some 317 heads measuring 67-68cc. On average, 862/706 heads with still have the smallest chambers.
Peter Fraumeni Did you notice I agreed with you, stated that it could go either direction, and that it applies to any head? IOW- Advertised chamber cc is essentially a rough “average”. 317s will typically be considerably bigger than a 862.
Slap in a cam, and let it eat. Seems like everything else people are spending hundreds of extra dollars on only nets like an extra 20 horse and costs an extra $1000+. That's just what I've learned from watching this channel and reading up in the facebook group. These engines are stupidly efficient in factory trim aside from the atrocious fuel and timing tables within the stock tune, and the little baby stock camshaft. That's why they respond so well to bigger cams and a solid tune.
Concerning the valve size talk at 4:20. Most hot rodders have heard about how a Ford 302 can bolt up 351W heads for bigger valves, providing better breathing at high RPM's, but causing poor cylinder-filling/torque at lower RPM's. The opposite is also true. Bronco's with a 351W have swapped-in 302 heads with smaller valves. It provided less air-flow at the higher RPM's, but when paired with the right cam and intake, the low-RPM grunt was improved. Sounds like the 862 head is the sweet-spot, for balancing all the factors. Thanks for the awesome info. You should write a budget LS book. there are services that will print-on-demand and ship them for you (doesn't have to be shiny paper or color pics)
Warren Michigan checking in video #9 every video in this series were great it’s actually gave me the confidence to build my own now and like I said in the last video my build will be on Woodward cruse this year because of this information instead of just a edam motor sitting in the garage on a stand thanks JR
The Driveway Engineer hell ya brother I grew up around Woodward and not in Birmingham or even Royal Oak hazel park the ghetto or better know as Hazel Tucky but my ex grew up in Royal Oak so I know the area very well I can show all the cool areas to hang out at best places to get good meals also but I gotta tell you make sure your cooling system is squared away the traffic can be a nightmare with all the classic cars on Woodward cruising
You saved me man.... I was that guy with the lq4 thinking about swapping to flat top pistions... I was leaning towards 706 heads but then heard about the "some might crack " great information brother.
Or a good majority of the early Gen IV 4.8's and 5.3's. I have 3 sets of 243s sitting here and not one of them came off of a 5.7 or 6.0.... They are just as much a run of the mill truck head as the 799 equivalents are. Same goes with the L33 5.3 Gen 3... either or. 243`s are not a special performance application head and why guys pay so much is more or less just ignorance. I left a set of 243`s last time out because they were on an LY2 4.8 in a 2008 van.. but yeah idiots here pay 300 dollars for cores because they somehow think they came from a Vette lol. Gen IV stuff is old now too lol...
Note: All LS heads have combustion chambers 3-5cc larger than what GM advertised. Please feel free to measure by cc’ing. The changes in compression between the castings are legit; the actual compression will be lower than expected if you use the “advertised” chamber sizes when calculating. 👍
Great info. You help to clear up much of the mystery regarding the heads for LS & much of the misinformation regarding an LS build in general. Thanks for taking the time to post your info & dis spell much of the BS going on out there. STAY REAL.
I found a L59 at the local scrap yard and went hunting for hours to find 243’s to swap before I paid for it because I was told they were better. Until I found out the L59 set up with the 846 heads makes 15 - 25hp over the more common 5.3 with other head combinations. Still need to turn it over to make sure it’s solid. Still haven’t deleted VATs. But I did get a wrench to turn it by hand and the cycle feels clean.
This is what I want people to avoid precisely. To go to all that effort and expense, just to have a worse result. Sell them to someone who doesn't watch my videos lol.
I picked up a core l99 6.2 for 40.00 for 823 heads and gen 4 rods. Took it apart all was wrong with it was broke valve spring. All bearings looked new. What i found out is they will replace a engine for blown head gaskets or anything in this day and time.
Yeah, transmissions are the same, alot of shops will just say "rebuild" to any problem, then you find out they are just swapping remans, not even doing the work. I was in a local place that didn't even have a fixture lol
@@TheDrivewayEngineer alot crooked shops. This engine looked new on the inside it blew my mind how they could do someone like that. Someone paid to put in a new engine and all it was was a 1hr fix
Was looking for vids on this. Im piecing a lq4 together. Found the short block for $400 and 862 heads for 100. The heads have been checked out and cleaned so i jumped on em. I broke my ls1. #7 piston and messed up my 853's
Good information, thanks for sharing your knowledge. Because of your video series, I’m strongly considering going this route over the traditional SBC in my Camaro.
There are a lot of guys at the local cruise night who should have bought shares in Summit before they started their build. I like your approach better. Cheeeeeeap horsepower!
Just found your page here and your Facebook group... You my friend are awesome, you're like Richard Holdener for those who aren't trying to spend 10k on a build... Looking forward to binging on your videos.
Sounds to me the numbers on the 862 is aluminum copies of the old 283 power pack heads thanks for the info and yes lowering the cc and upping the compression ratio is always better than shaving heads
I’d be careful; cam accordingly if running 11.0-1+ SCR on pump gas.⛽️ What I see and don’t recommend is running 862/706 on a 6.0 w/ stock cam or “Torque” cam designed to build cylinder pressure on pump gas. Even on 91-93 this particular combo will be subject to both inaudible and audible detonation.
The thing about dropping compression to run more boost isn't nessisarly about power but about having a margin of saftey with high boost. It's possible to run 12:1 compression and 20 lbs of boost but things have to pretty much be perfect all the time. When they're not is when you risk going boom.
Matt from Sloppy tested some heads & had the same conclusion. Although the 241 & 243 heads outflowed the measly 706's, at the end of it all the lowly 706 made the most power. Whoda thunkit?
What you got right: bumping compression for your LQ4 with 862 heads gets you in the 10.5+ to 1 range and will be ideal for nat asp h/p on pump gas. What you fail to mention: For LQ9 which already has 10 to 1 compression, the 862 heads would put you over 11 to 1 and out of the pump gas range. The 243s may be a better choice for ideal compression ratio on that platform and im seeing them everywhere right now for $300 which is a great value.
First, I wouldn't bother paying extra for an LQ9. But if there was one in the yard, I would still take it and still put 862's on it. My LQ4 runs 87 octane with them, both of my LQ4's do in fact. I guess I'd probably move to premium at 11:1, but it's hardly out of pump gas range, the LS7 is 11:1 from the factory.
@@TheDrivewayEngineer if an lq9 (flat top piston)with 64cc chambers is 11 to 1 compression, then the 862s with 61cc chambers are going to detonate on pump gas. Now your pulling your motor apart and buying dished pistons.
Great video 👍👍 I know it's 4 years old. I bought an LQ9 out of a 2005 escalade with 115K miles for $200 It has 317 heads. I know it's 10.08 to 1 compression. Going to put it in a 2007 chevy classic with a manual transmission. Going from v6 to v8, I followed your process and got everything I needed to do a successful swap. Going to put a BTR Truck cam and springs in it. Anything else I can do to the heads make NA power? Looking for 450 to 500hp at the flywheel. Any help or advice, thanks
I can get the 706 heads for 200.00 and they’re not the castech heads. 50.00 sounds nice but maybe people are catching on now LOL. These will also be on a LQ4 with a stage 2 or 3 low lift truck cam. I think it will be a stout setup for my K5 blazer that spends it days under 6000 rpm.
Man you are funny at the same time you have knowledge I just subscribe you be having me cracking up I am sitting back just listening so I can be great also I'm almost done with my build LS1 2000 WS6
Hey bud so I got this yukon 2500 with a 6.0 in it. I wanted to do a cam (summit cam for like 200 ish) and I wanted to also slap 862 heads on it to bump compression up. I heard that they flow less than the 317 heads that came with it... but a lot of it is above 6k rpms and I use the thing for towing and use on the street. Thanks for the video man
So it depends on the use. Idk everything about ls heads that's why I'm here. But I've experienced boost on 862 and 317 heads so far. It seems to me the 317 heads like the boost more than the heads I have used. Just my two cents for those browsing comments. Obviously this guy seems to know more than me. But judging by the numbers u have here, that explains why the 317 heads loved boost and the engine held 16psi reliably for several years
I love your candid view of the subject matter. No beatin' around the bush here. I did a repower of my 01 2500HD 6.0 with a later ('03) 6.0 and used 862 heads with a stage 1 truck cam(Stage 1 NSR Truck Cam 206/212 .515/.522). Used stock drive by cable throttle body with stock truck manifold and flex fuel 5.3L injectors. ECM was tuned by Black Bear performance for 91 octane fuel for this cam and flex fuel injectors. This truck never ran so good. Night and day difference. Instant throttle response with seat of the pants torque increase. Thanks for steering me in the right direction on the proper head choice for my repower. Keep the great videos coming!!!
Do what you want but for my build and the research I did led me a total different direction. I’m looking to make decent power and for my 6 liter I went with the 821 LS3 head. If you are building a 6.0 these are the best flowing head period. 821 or 823. I had mine cnc ported by Texas speed for even better flow. Anyone that thinks flow bench numbers don’t matter is kidding themselves. An engine is an air pump. More air and fuel in more power out. 317 heads work well with turbo or blower but for my nitrous build these 821 heads are the best factory head out there. They will only work on 6.0 and 6.2 because you need a 4 inch bore due to valve size.
A very small percentage of 706 castec heads have cracking issues. A much more common failure of 706 heads (and 862) as they age in the market is corroded coolant passages from cylinder head to block. The casting issue with the limited number of castec heads has for the most part worked the majority of these heads out of the market. In the last 10 years i have a steady decline of cracked failed 706 and none in since covid started (2020) I don't process as many las heads as some shops, but I do between 150 and 200 pair a year of all LS castings. I think the 706 horrors are behind us. What to watch out for is the repaired 706 castings. Some shops a few years back got hold of GM core rejects. For a while there were "tig Welded" head bolt boss repairs heads being sold mostly on the internet. I had a 2 pair come through the shop. The weld repair is a good theory, but the execution of the repair was substandard. Both pairs the cracks were fused with a tig process. In both cases the repairs failed because the original crack was not removed or ground and refilled. I understand why the shop that performed the repair did not grind and refill damaged metal. There is no access to feed filler metal while tig welding the area. The best that can be done is to remelt and fuse the top layer. The issue is this does not remove the crack and it does not remove impurities deposited by the coolant leaking through the crack. It was a poor bandaid repair that failed.
"You're stoooopid, I got sum hades on my car"😂😂😂😂 Had me dying from the jump, couldn't stop laughing through first half of video. Had to watch it again! " If you're Bob Lutts you don't need yo be watching my video"😂😂😂 "You're stoooooopid"
@@TheDrivewayEngineer, my face was literally that emoji! My wife said" what the hell is wrong with you, why are you crying and laughing", all I could do was say" you're stooooopid" "shooooooot"! She's pissed now because I've been walking around the house the last 10 minutes repeating it over and over😂😂😂😂😂😂😂
I got a 2000 c5 corvette LS1. Planning on throwing a Texas speed cam Torquer V4 CAM. The heads are 241, but I got a pair of 706 heads that are on a 5.3 from a 04-05 Silverado. My question is if I throw the 706 on the ls1 how much compression will it raise and would be a bad choice to run them? They will remain stock I won’t do any work to the heads.
I have a set of 862 heads i got for 40 bucks in good shape and plan on dropping a lq4 from a 06 chevy express in my squarebody So with those 862 heads, engine, cam, springs and tbss intake should i make good power ?
Is it worth doing a cam for my Gen 3 iron block 5.3L with 862 heads and LS6 manifold am I going to see worthwhile gains. I like your post I get so sick of people taking this stuff so far and wasting money just to get couple horse here and there.
Question is the 706/862 are the best choice due to compression would getting some 243 milled down to where you don’t loose any compression. Would those be a better choice at that point due to them flowing better? I have a 5.3 with flat tops and a 223/226 camshaft. Just looking for the best choice. 706 or 243 either or will be ported
Yeah i agree you videos was a huge help but i question say im going to do every thing discribe in your videos and am going to. But what if i wanna run t56 trans on back i see people say they bolt up but what about everything else like pcm and do you have a video on what i need
The 862 heads were the most commonly cracked heads .they crack at the head bolt mating surface and between the bore and the water jacket.they are cast aluminum and prone to casting shift..the 706 heads had a lower percentage of being cracked due to it spm casting and smooth casting surface..i work at a dealership..we have stacks of cracked 862s.not many 706s..most machine shops say when they get a set of 862s that they are prone to crack..magnaflux your 862s before dumping money into them..
I'm glad you have good luck with your 862s..at the dealership when a customer complains of coolant loss we pressure check the block with valve covers off and watch the coolant seep around center head bolts..great video...good info on casting numbers..
Dude you make the videos I’ve been looking for. Simple , straight up, and actually included me in the “99 percent” 😂😂
Thanks! I'm glad they are helping you
I’m the 99 percent !
I'm new to your channel and I'm part of the 99% of people that don't have a lot of money but can put together a fast small block to run around the streets with out of a junkyard. Love the videos. Keep up with the educational videos.
Junkyard LS, new cam and a bunch of used tires for burnouts sounds like an awesome Saturday
You have been a awesome resource of knowledge on LS engines. I absolutely love that you tell it how it is.
Back when I wanted to build a motor. It was prc 2.5s all the way gotta have em. Now that my wallets out. 317s or 862s all day. Great vid
You are absolutely one of the few people that I have heard make such an intelligent statement about higher compression and boost. Apparently very few people are aware of this. I keep trying to tell people this oh, that you do not need to have 7 to 1 compression to run boost. There are actually people who run 14 to 1 compression and then boost. Regardless the reason it is going to have a snap your response is because it will still have the immediate torque. We don't have to wait for the turbo to spool up, which means you can go with a bigger Turbo for higher-end power but still have power in the low end. This also means that you don't have to overwork the turbo as much. I am currently finishing up a forged 384 Stroker with a 10.5:1 CR NA, & with only 10 PSI from the twin turbos, i am over 820 ft lb torque/ 715 HP. Those turbos are barely breaking a sweat.
Diesels on 18-wheelers use 18:1 compression ratio plus a turbo, but for different reasons. That being said, it comes down to heat management. The vulnerable parts are exhaust valves, the exhaust side of the piston, and the turbo exhaust temps.
@@ronroberts110 very true!
It's an old wives tail that just won't die like Pennzoil or destroked engines rev faster
Maybe some people worry about the ol David that is pre detonation....
But with E-85 pretty much everywhere with it's higher resistance to engine knock and its characteristic cooler burning flame... you can have your cake and eat it too. So long as you set your fuel system up to use it. But really... if you're ready to swap heads and possibly engine swap all together... doing a fuel system along with it isn't really much to add on
I run my 10.5:1 6.0 on 87 octane
Great info, my junkyard 5.3 came with 862 heads
I picked up a pair of 862's for my firebirds 5.7ls today. Thanks for the video.
Great video. I have 862’s that are in mint condition that came out of a very low mileage 5.3. And I have a set of 799’s that came out of a torched 5.3. 799’s will need all work done to them. People keep telling me to run the 799’s and I’m like nope, 862’s are what I’m going to run.
Another great video, I’m just getting into the LS scene and need all this information. Thank you
Thank you for the education. I’m learning so much from your channel.
Good info! Thanks for taking the time to do this. Really like your no nonsense and cheap approach to LS builds.
I blew my lq4 up and found a lq9 block cheap and when I got the block it needed to be bored so I went .030 with +6 cc flat top pistons and the block was decked .010 and heads shaved .010 asa hot cam with 873 iron heads. I really like your info video
Before I had an ls I thought the car heads / later truck heads were what I needed until I started looking at the combustion chamber sizes. Everyone said to get the 799 heads off a late model 5.3 but with an 04 5.3 I’d be going up in cc’s and down in compression. Being that I’m not using a turbo I decided to listen to mr holdner where he shows the 706 / 862 heads make the most power so I got some junk yard heads, cleaned them, lapped the valves, and put some el cheapo eBay springs on them, then I picked up a Chinese 615-183 intake for $65 brand new, ls7 lifters, summit Vortec towing cam and it’s a totally different truck
Pretty comprehensive and to the point. Thanks. I'll have to bookmark this vid. I've always preferred a smaller CC for quicker burn, better thermal efficiency. Its all aluminum after all, it can dissipate the heat much better than cast iron, therefore these engines can take the spark advance booster so sought after, w/o pre-detonation. Would like to see them design a head w/ more dedicated cooling to help the overall thermal efficiency.
the 706 head made the most power on hot rod magazine dyno at west tech, get you some of that baby.
I have my set of 862 heads put up thanks for the great video
C5 corvette owners with 241 heads typically upgrade to ported 243 or 799 with a new cam.
Great info the buddy. I too am wanting to do an LS on the cheap side and you’re making it easier.
Thanks! I'm glad it's helping!
I've an LS motor and I can do burnouts with it as a stock chevy motor, no changes, none.
Cheap burnouts is what it's all about 🤑
This guy get's it lol.
Unless you just bought new tires like I just did. But I love my burnouts more lol
Cheap on reliable crap
I just read an article a few weeks ago that said the 706 heads were a game changer on the LQ4. I hopped on Facebook and found a pair of them about an hour away for $50. Thanks for confirming what I was crossing my fingers for! Subscribed!
I paid 50 for mine lol, then sold my 243's for 300 lol
Ha! That's awesome! My LQ4 had the 873 heads on it. This build is just going to be for fun on the street. I'm going to put it on the track and see what it will do, but going to build a more serious engine for next year. I bought my car as a roller. It came off of the track running in the 8's at 160+ mph with a twin turbo 5.3. It was somewhere in the neighborhood of 1200hp. I'd like to get it back to doing that someday!
Just discovered your channel,very good information on the heads !!Loved the printed specs and the flow numbers!!Great on what heads came in which vehicles too.Look forward to seeing all you videos 👍👍
Just left my local junkyard where I've located 3 LSs. 2 6.0s and a 5.3 one of the 6.0s even had the 4l80 in it!
I have a 5.3 with 862 heads and a LQ4. I was thinking the same as you...
LQ4 shortblock with the 862 heads, maybe smooth out the ports by hand, add a cam, and go party.
I heard an engineer from Texas Speed said that he’d give up port CFM for compression any day of the week, and it makes sense. Compression will increase power everywhere.
Back in the 70's and 80's the SAE did a bunch of studies because they dropped compression into the toliet to deal with unleaded gas.
Compression was the single largest factor in power and efficiency, and power rose faster than knock with compression, both static and dynamic. Power also fell off faster than knock.
@@TheDrivewayEngineer Which is why Mazda in their skyactiv engines are like 14 or 15 to 1.
Yeah but you still need enough air or your choking the engine.
Yep, I agree, with my running LQ9 (all original) I am going to simply freshen it up, (check oil pickup tube seal) and slap it in . Run it, see how I like it, then I can play with cams and what have you. Good education thanks.
How did it go?
@@FilthyPancakes Frankly, it didn't. I ended up tearing the engine down and could hardly get the cam out, although lifters and lobes look good. Fair amount of black carbon, but no sludge or metal, tested, and had 165 to 180 PSI in all 8 cyls dry prior. Still had crosshatch on walls and pulled one rod bearing looked good. So, now I am taking in to shop, have them do inspection and install stage two cam / bearings. put it back together and hopefully run it. Fingers crossed, potential for change without notice! LOL
I agree with host about 862s but some are more volume in combustion chamber than 61cc. Some are much more like 64.5cc so do check their chamber volume or you may be disappointed if you looking for bolt on compression increase. The higher volume chamber heads are for CA nox reduction, just a theory.
Peter Fraumeni
It’s true that the chambers can vary in size, but that goes for any head. They could also be smaller as well; like some 317 heads measuring 67-68cc. On average, 862/706 heads with still have the smallest chambers.
Did you notice I said ...SOME?
Peter Fraumeni
Did you notice I agreed with you, stated that it could go either direction, and that it applies to any head?
IOW- Advertised chamber cc is essentially a rough “average”. 317s will typically be considerably bigger than a 862.
Slap in a cam, and let it eat. Seems like everything else people are spending hundreds of extra dollars on only nets like an extra 20 horse and costs an extra $1000+. That's just what I've learned from watching this channel and reading up in the facebook group. These engines are stupidly efficient in factory trim aside from the atrocious fuel and timing tables within the stock tune, and the little baby stock camshaft. That's why they respond so well to bigger cams and a solid tune.
Concerning the valve size talk at 4:20. Most hot rodders have heard about how a Ford 302 can bolt up 351W heads for bigger valves, providing better breathing at high RPM's, but causing poor cylinder-filling/torque at lower RPM's. The opposite is also true. Bronco's with a 351W have swapped-in 302 heads with smaller valves. It provided less air-flow at the higher RPM's, but when paired with the right cam and intake, the low-RPM grunt was improved. Sounds like the 862 head is the sweet-spot, for balancing all the factors. Thanks for the awesome info. You should write a budget LS book. there are services that will print-on-demand and ship them for you (doesn't have to be shiny paper or color pics)
Warren Michigan checking in video #9 every video in this series were great it’s actually gave me the confidence to build my own now and like I said in the last video my build will be on Woodward cruse this year because of this information instead of just a edam motor sitting in the garage on a stand thanks JR
That's awesome! I want to make it down there as well, maybe we can hang out!
The Driveway Engineer hell ya brother I grew up around Woodward and not in Birmingham or even Royal Oak hazel park the ghetto or better know as Hazel Tucky but my ex grew up in Royal Oak so I know the area very well I can show all the cool areas to hang out at best places to get good meals also but I gotta tell you make sure your cooling system is squared away the traffic can be a nightmare with all the classic cars on Woodward cruising
You saved me man.... I was that guy with the lq4 thinking about swapping to flat top pistions... I was leaning towards 706 heads but then heard about the "some might crack " great information brother.
I've been that guy too, too much money into too little result.
LS2 came with 243 heads in the corvette and 2006 cts-v's also
I believe the LS4 got them as well
I got my 243's off a 2008 trail blazer ss
05-06 gto too as well as the 6.0 ssr.
Or a good majority of the early Gen IV 4.8's and 5.3's. I have 3 sets of 243s sitting here and not one of them came off of a 5.7 or 6.0.... They are just as much a run of the mill truck head as the 799 equivalents are. Same goes with the L33 5.3 Gen 3... either or. 243`s are not a special performance application head and why guys pay so much is more or less just ignorance. I left a set of 243`s last time out because they were on an LY2 4.8 in a 2008 van.. but yeah idiots here pay 300 dollars for cores because they somehow think they came from a Vette lol. Gen IV stuff is old now too lol...
PickardvilleSRT8 so all the 243 heads from corvettes, trucks and vans the same head?
Note: All LS heads have combustion chambers 3-5cc larger than what GM advertised. Please feel free to measure by cc’ing.
The changes in compression between the castings are legit; the actual compression will be lower than expected if you use the “advertised” chamber sizes when calculating. 👍
Great info. You help to clear up much of the mystery regarding the heads for LS & much of the misinformation regarding an LS build in general.
Thanks for taking the time to post your info & dis spell much of the BS going on out there.
STAY REAL.
yay i got 862s cam swap intake and exhaust are on the way
Not only do I like the information and down home opinion, but the immatations make happy, happy, happy!
"Yep" I'm a real big fan of keep it simple stupid, I agree with you!
SWEET my 03 Silverado 4.8 came with 862’s love me some compression
I traded my old 350 four bolt main for a LQ9 and found a extra clean set of 823 heads with rockers for cheap,,,,, waiting on my summit cam,,,,,
I really like your explanations! I am not a mechanic but if I see someone do something I got it forever. Can’t wait to find my LS/Truck Vortex engine
I'm a big believer in hands on learning, I do the same.
I found a L59 at the local scrap yard and went hunting for hours to find 243’s to swap before I paid for it because I was told they were better.
Until I found out the L59 set up with the 846 heads makes 15 - 25hp over the more common 5.3 with other head combinations.
Still need to turn it over to make sure it’s solid. Still haven’t deleted VATs. But I did get a wrench to turn it by hand and the cycle feels clean.
This is what I want people to avoid precisely. To go to all that effort and expense, just to have a worse result.
Sell them to someone who doesn't watch my videos lol.
do u have 243's ur looking to get rid of?
@@v8powa466 nope, sold them the day I took them off
@@TheDrivewayEngineer sounds like CK_32 might have them.....
I picked up a core l99 6.2 for 40.00 for 823 heads and gen 4 rods. Took it apart all was wrong with it was broke valve spring. All bearings looked new. What i found out is they will replace a engine for blown head gaskets or anything in this day and time.
Yeah, transmissions are the same, alot of shops will just say "rebuild" to any problem, then you find out they are just swapping remans, not even doing the work.
I was in a local place that didn't even have a fixture lol
@@TheDrivewayEngineer alot crooked shops. This engine looked new on the inside it blew my mind how they could do someone like that. Someone paid to put in a new engine and all it was was a 1hr fix
Agree on 862. I want to swap out my perimeter bolt heads on my LS1 and swap to 862 so bad.
Was looking for vids on this. Im piecing a lq4 together. Found the short block for $400 and 862 heads for 100. The heads have been checked out and cleaned so i jumped on em. I broke my ls1. #7 piston and messed up my 853's
I got the stock 99 c5 Corvette with the ls block. Performs just fine for me. Video was very thorough and informative. ✌🏾💯
That's the real lesson, none of the heads are significantly better or worse than the others
I just answered all my questions I was gonna ask you. Good content for sure !
Good information, thanks for sharing your knowledge. Because of your video series, I’m strongly considering going this route over the traditional SBC in my Camaro.
6.0 block with a 4.8 crank. Do that build. Super cool info on this video. Thx
There are a lot of guys at the local cruise night who should have bought shares in Summit before they started their build. I like your approach better. Cheeeeeeap horsepower!
Just found your page here and your Facebook group...
You my friend are awesome, you're like Richard Holdener for those who aren't trying to spend 10k on a build...
Looking forward to binging on your videos.
I've read most of his books lol, not surprising we think alike.
Sounds to me the numbers on the 862 is aluminum copies of the old 283 power pack heads thanks for the info and yes lowering the cc and upping the compression ratio is always better than shaving heads
I’d be careful; cam accordingly if running 11.0-1+ SCR on pump gas.⛽️
What I see and don’t recommend is running 862/706 on a 6.0 w/ stock cam or “Torque” cam designed to build cylinder pressure on pump gas. Even on 91-93 this particular combo will be subject to both inaudible and audible detonation.
For the record, and yes, I'm going to be that guy, Bob Lutz was a big 3 auto executive. Jeff Lutz is a drag week legend.
Eh, can't win em all lol
You are correct! And knowing is half the battle, yo joe!
Yeah well suck both Lutz.
Sorry I listened to the entire video and this guy needs to cheer up.
Finally a guy that knows what he’s doing. Your not racing a flow bench!!!
The thing about dropping compression to run more boost isn't nessisarly about power but about having a margin of saftey with high boost. It's possible to run 12:1 compression and 20 lbs of boost but things have to pretty much be perfect all the time. When they're not is when you risk going boom.
Love the channel. Thank you for the help!
Matt from Sloppy tested some heads & had the same conclusion. Although the 241 & 243 heads outflowed the measly 706's, at the end of it all the lowly 706 made the most power.
Whoda thunkit?
Yeah, flowbench isn't everything lol
What you got right: bumping compression for your LQ4 with 862 heads gets you in the 10.5+ to 1 range and will be ideal for nat asp h/p on pump gas.
What you fail to mention: For LQ9 which already has 10 to 1 compression, the 862 heads would put you over 11 to 1 and out of the pump gas range. The 243s may be a better choice for ideal compression ratio on that platform and im seeing them everywhere right now for $300 which is a great value.
First, I wouldn't bother paying extra for an LQ9.
But if there was one in the yard, I would still take it and still put 862's on it.
My LQ4 runs 87 octane with them, both of my LQ4's do in fact.
I guess I'd probably move to premium at 11:1, but it's hardly out of pump gas range, the LS7 is 11:1 from the factory.
@@TheDrivewayEngineer if an lq9 (flat top piston)with 64cc chambers is 11 to 1 compression, then the 862s with 61cc chambers are going to detonate on pump gas. Now your pulling your motor apart and buying dished pistons.
Guess we'll have to agree to disagree, because I'd run it all day
I like the way you think. Subscribed
Smaller chambers equall cheap/more horesepower. Great video. You dont need big intake valves for the street. Not gonna use upprr Rpm's on the street.
Exactly, the small chamber heads beat the big valve heads everywhere but 7000 RPM regardless of what the flowbench says.
Your exactly correct my man GREAT JOB, KEEP UP ALL THE GREAT WORK👍.
Great video 👍👍 I know it's 4 years old. I bought an LQ9 out of a 2005 escalade with 115K miles for $200
It has 317 heads. I know it's 10.08 to 1 compression. Going to put it in a 2007 chevy classic with a manual transmission. Going from v6 to v8, I followed your process and got everything I needed to do a successful swap. Going to put a BTR Truck cam and springs in it. Anything else I can do to the heads make NA power? Looking for 450 to 500hp at the flywheel. Any help or advice, thanks
There's honestly not much bang for the buck in the heads.
I can get the 706 heads for 200.00 and they’re not the castech heads. 50.00 sounds nice but maybe people are catching on now LOL. These will also be on a LQ4 with a stage 2 or 3 low lift truck cam. I think it will be a stout setup for my K5 blazer that spends it days under 6000 rpm.
Elsewhere on the Ytube , dyno results agree
Love the channel, very useful info.. thank you
706 or 862 , just drop the old thoughts about the original SBC valve size
You are always on point!
Been trying to find this info for awhile...all the info I've read/watching has never layed it out in simply cut and dry form...thanks...
Glad it helped!
Man you are funny at the same time you have knowledge I just subscribe you be having me cracking up I am sitting back just listening so I can be great also I'm almost done with my build LS1 2000 WS6
Thanks for these videos theres so many parts out there it's hard to decide. Trying to figure out a head cam combo for my 00 ss camaro.
Man I gotta catch up on ALL your LS videos lol great content brother!
Thank you!
Hey bud so I got this yukon 2500 with a 6.0 in it. I wanted to do a cam (summit cam for like 200 ish) and I wanted to also slap 862 heads on it to bump compression up. I heard that they flow less than the 317 heads that came with it... but a lot of it is above 6k rpms and I use the thing for towing and use on the street.
Thanks for the video man
So it depends on the use. Idk everything about ls heads that's why I'm here. But I've experienced boost on 862 and 317 heads so far. It seems to me the 317 heads like the boost more than the heads I have used. Just my two cents for those browsing comments. Obviously this guy seems to know more than me. But judging by the numbers u have here, that explains why the 317 heads loved boost and the engine held 16psi reliably for several years
Why didn't corvettes and camaros and TAs come with 706 or 862?
To save some pussy for the rest of us.
So 862s are the best heads for lq4 to boost compression?
I love your candid view of the subject matter. No beatin' around the bush here.
I did a repower of my 01 2500HD 6.0 with a later ('03) 6.0 and used 862 heads with a stage 1 truck cam(Stage 1 NSR Truck Cam 206/212 .515/.522). Used stock drive by cable throttle body with stock truck manifold and flex fuel 5.3L injectors. ECM was tuned by Black Bear performance for 91 octane fuel for this cam and flex fuel injectors.
This truck never ran so good. Night and day difference. Instant throttle response with seat of the pants torque increase.
Thanks for steering me in the right direction on the proper head choice for my repower.
Keep the great videos coming!!!
I got the 806 ls heads on 6.0lq4
do you have to run premium gas with the setup
I don't, but it's all in the tune
Do what you want but for my build and the research I did led me a total different direction. I’m looking to make decent power and for my 6 liter I went with the 821 LS3 head. If you are building a 6.0 these are the best flowing head period. 821 or 823. I had mine cnc ported by Texas speed for even better flow. Anyone that thinks flow bench numbers don’t matter is kidding themselves. An engine is an air pump. More air and fuel in more power out. 317 heads work well with turbo or blower but for my nitrous build these 821 heads are the best factory head out there. They will only work on 6.0 and 6.2 because you need a 4 inch bore due to valve size.
Yeah, those extra 18 hp are really gonna make a difference at Race Wars for you
A very small percentage of 706 castec heads have cracking issues. A much more common failure of 706 heads (and 862) as they age in the market is corroded coolant passages from cylinder head to block. The casting issue with the limited number of castec heads has for the most part worked the majority of these heads out of the market. In the last 10 years i have a steady decline of cracked failed 706 and none in since covid started (2020) I don't process as many las heads as some shops, but I do between 150 and 200 pair a year of all LS castings. I think the 706 horrors are behind us. What to watch out for is the repaired 706 castings. Some shops a few years back got hold of GM core rejects. For a while there were "tig Welded" head bolt boss repairs heads being sold mostly on the internet. I had a 2 pair come through the shop. The weld repair is a good theory, but the execution of the repair was substandard. Both pairs the cracks were fused with a tig process. In both cases the repairs failed because the original crack was not removed or ground and refilled. I understand why the shop that performed the repair did not grind and refill damaged metal. There is no access to feed filler metal while tig welding the area. The best that can be done is to remelt and fuse the top layer. The issue is this does not remove the crack and it does not remove impurities deposited by the coolant leaking through the crack. It was a poor bandaid repair that failed.
That's pretty interesting!
@@TheDrivewayEngineer BTW subbed love the info you have put out. think i have covered a few years in the last few hours lmfao
I've got an LQ4.... you still think it's better to just slam a cam in and run it?
"You're stoooopid, I got sum hades on my car"😂😂😂😂 Had me dying from the jump, couldn't stop laughing through first half of video. Had to watch it again! " If you're Bob Lutts you don't need yo be watching my video"😂😂😂 "You're stoooooopid"
That's like 90% of the comments usually lol
@@TheDrivewayEngineer, my face was literally that emoji! My wife said" what the hell is wrong with you, why are you crying and laughing", all I could do was say" you're stooooopid" "shooooooot"! She's pissed now because I've been walking around the house the last 10 minutes repeating it over and over😂😂😂😂😂😂😂
I got a 2000 c5 corvette LS1. Planning on throwing a Texas speed cam Torquer V4 CAM.
The heads are 241, but I got a pair of 706 heads that are on a 5.3 from a 04-05 Silverado. My question is if I throw the 706 on the ls1 how much compression will it raise and would be a bad choice to run them? They will remain stock I won’t do any work to the heads.
This is nonsense, just put the cheapest cam in and have fun
I got 5.3l l33 it has 241 they I'm sticking with them
That's the real takeaway, unless they're free, none of them are really worth swapping to.
243/799 heads came on 4.8/5.3 trucks up to 2012.
If you got em roll with em, I just wouldn't bother looking for them. Also, the truck heads don't get the fancy springs.
Another good and informative video, thanks...
My 13 Silverado came with 243 heads and 373 gears, I've been wanting to mod it for more power but dont have a clue
B3N cam,stall,tune
Converter most bang for the buck
Thanks again for sharing bro I really appreciate you
Any time
I have a set of 862 heads i got for 40 bucks in good shape and plan on dropping a lq4 from a 06 chevy express in my squarebody So with those 862 heads, engine, cam, springs and tbss intake should i make good power ?
It won't change your life, it will be better than it was
Are you still going to do a video on a “all motor” build???? I need ideas on my lq4 build. Thanks
That's what these 862 heads are for
I have the 862 and the 706 which should I used
If I had both in hand I'd use the 862's
243/799 heads are the better for na for anything with less then a 4 inch bore
I have an 02 lq4 putting on a set of 862 heads btr stage 3 truck cam should I get bigger injectors, thanks I’d appreciate your input
If you can find flex injectors or 8.1 injectors, that will give you a cushion, but you don't really need to .
The Driveway Engineer thank you sir!
Is it worth doing a cam for my Gen 3 iron block 5.3L with 862 heads and LS6 manifold am I going to see worthwhile gains. I like your post I get so sick of people taking this stuff so far and wasting money just to get couple horse here and there.
A cam and whatever springs you need to run it are the biggest, easiest gains for these.
@@TheDrivewayEngineer Thank you.
Question is the 706/862 are the best choice due to compression would getting some 243 milled down to where you don’t loose any compression. Would those be a better choice at that point due to them flowing better? I have a 5.3 with flat tops and a 223/226 camshaft. Just looking for the best choice. 706 or 243 either or will be ported
You're chasing like 8 hp for hundreds of dollars.
@@TheDrivewayEngineer thanks for clarifying that.
Yeah i agree you videos was a huge help but i question say im going to do every thing discribe in your videos and am going to. But what if i wanna run t56 trans on back i see people say they bolt up but what about everything else like pcm and do you have a video on what i need
You don't need anything, buy it, bolt it together, it's a factory combination
What about an LS6 , any factory heads that would bump the compression a bit over the 243
The info is in the video, all the chamber sizes are there.
The 862 heads were the most commonly cracked heads .they crack at the head bolt mating surface and between the bore and the water jacket.they are cast aluminum and prone to casting shift..the 706 heads had a lower percentage of being cracked due to it spm casting and smooth casting surface..i work at a dealership..we have stacks of cracked 862s.not many 706s..most machine shops say when they get a set of 862s that they are prone to crack..magnaflux your 862s before dumping money into them..
I'm not magnafluxing anything, or dumping any money into any of them 😂
I'm glad you have good luck with your 862s..at the dealership when a customer complains of coolant loss we pressure check the block with valve covers off and watch the coolant seep around center head bolts..great video...good info on casting numbers..
I’m gonna say the head that comes with the moter
How do you torque the used head bolts?
Jeff Lutz? Bob is that his uncle from iskeegohome...