This is so interesting, wish I still had my 73 Caprice with the 400. Would be such a thrill to work in your shop, even as a gofer, or to man the broom, just to watch and learn....
400 sbc's are my favorite. For the ultimate poverty build you can't beat a vortec headed 400 with a mild flat tappet cam. Only problem is that good cores are extremely scarce because these were only used in the big full sized cars and heavy duty 3/4ton and 1 ton vans and trucks so if you are planning to build a really nice 400 starting with an aftermarket block is the way to go, most OEM blocks floating around are usually in need of more money in machine work than it's worth.
I've got about a dozen standard bore 400 blocks, but getting hard to find now. Alot people didn't like them. I love them. Lots of power and torque from them.
@@Myvintageiron7512 Great video! Dart has an SHP block that already has the 4.125" bore and you can get it with either 350 or 400 mains size depending on what you want. The block is about $2350 from Jegs. I've been debating between a 350 or 400 build (from an SHP Dart block). Starting to lean towards the 400 with 350 main size and 6" rod. Just need to grow some more money on the tree out back...
So, back in the day, 1974, I built a 400 SBC for my 64 Nova. I used stronger rod bolts and studded the main caps. I installed a scraper and Moroso cut out pan and a screen windage tray. 462 casting heads with 2.02 Intake and 1.600 Manly stainless steel valves with Crower conical springs. Screw in studs and guide plates. A Sig Erson High Flow 1H cam and a Summers Brothers gear Drive. A Wieand X-pert intake and Holly 850 DP Carb with an Accel dual Point Tack Drive Distributor. I limited the RPMs to 5500 due to the acute Rod Angle of the 400 SBC. Trans was a built 350 Turbo, Manual Shift and 373 gears in the 12 bolt rear end. Car weighed 2650 lbs and ran 11.80's @ 114 in the 1/4 mile at Irwindale Raceway. Loved that car. Love the 400 SBC. Much under rated Chevrolet engine.
I really appreciate your knowledge and you sharing these videos. I have learned so much from watching your videos. I am in the final stages of building a 351 W for a 69 Mustang. Thank you for taking the time to explain some of the more complicated stages of engine building. You have really opened my eyes as to how each and every part of an engine interacts with the others.
At one point Clevite made main bearings to install a 350 crankshaft in a 400 block. It produced a 377 CID sbc. I think they were used for circle track. I haven't heard of this combo in years.
That's actually pretty quick of you because it can be extremely difficult welding the two different types of metals getting the heatsink right great idea
I have a fresh 406 on a stand waiting for something. Have a 421 build at the machinest. And luckily at the moment I still have access to a couple dozen 400 blocks. Also have a fresh 355 waiting as well. Also have a handful of bbc builds going. Can never have enough spare engines.
@Myvintageiron - there are a couple of things you missed. 1. 400 SBC's have a bigger main journal on the crank. mains are 2.65 and rods are 2.10. all small blocks except the 400 used either 265,283 and 327 until 66 used the small 2.30 main journal and 2.00 rods. or 67 and latter 262,267,302,305,307,327 and 350 all used the medium main journal 2.45 and 2.10 rod journals. 2. you did mention connecting rods were different but left out a really important part. all small blocks except the 400 use a 5.7 inch road. the 400 uses 4.565 rods, but they had to shave the corners on the top of rod bolts to keep them from hitting the cam. this is really important when using high lift or retro fit roller cams in a 400. most aftermarket rods already account for this since the 383 storker kits are so popular. 3. one last thing to know on the 400 blocks. the 400 block uses thin wall casting to save weight, and ironically the 4-bolt wall block is weaker than the 2-bolt block. 400 4-bolt blocks have a tendency to crack in the main webs near the outer bolts because of the thin castings. if you are building one for mild performance, they are great. but when you get the 400HP you will start cracking main webs on 4-volt blocks. and its not much higher for 2 bolt blocks. the best solution is splayed main caps. but that just adds to cost of machining, and you need a machine shop that knows what they are doing when align boring. most engine shops suck at this for some reason. last thing on the 400 is cost, it is significantly more expensive to rebuild a 400 than a 350. which is another reason the 383 kits are so popular. you get all the torque and HP of a bigger motor, but with out the hassle/cost of building a 400. dont get me wrong, the 400 has a place, but it is not for high performance. when built for torque and stuffed in a land yaught like a Caprice or a Monte Carlo they are great. but honestly if you are trying to make big horsepower numbers you are better of with a Big Block 454. going form a 400 to a 454 is about like going from a 350 to a 400. only the BBC will take anything you can throw at it as long as you keep oil in it and make massive power. and all iron Big block is only 200lbs heavier than an all iron SBC. which is another reason the 383 kits are so popular. in my opinion its not worth building a 400sbc uless it is a matching numbers car. the 383 kit overcomes issue with the weak castings, and the BBC is much better for big heavy applications.
My last 400 had 5.7 rods 8cc dish piston zero decked . With 186 heads heavily ported by myself. 480 lift cam rpm intake. It put a 3900 lb. Monte carlo into the 11s. That thing was a hoss. Love the 400 sbc.
I scored a 400 a few months ago. I scored two sets of Camel Hump heads. 461 and 462. Im going to put the 462s on since the area below the spark plug hole is sloped instead of straight down like the 461s. So should be a few more cc of volume for better pump gas manners. As soon as I get more parts im gonna do videos on putting the engine together. And eventually put it in my 79 Z28.
Yup ground many 400 cranks for 383 cubes 030 over bore of course. Did your notice the core plugs on the side of the block, there were 2. Did you notice the boss on the side of the block aswell. When the 3rd core plug is machined there to except a core plug (frost plug) that block well be a 4 bolt block. Trust me. I worked on tons of those in machine shop back in the day.
Friend of mine in HS had a 73 Impala with a 400 2bbl. It actually performed very well up to the 2bbl running out. One wheel peel for a mile. Kept it for years and other than plugs and oil and filters she was very trouble free.
Good friend of mine had that same year Impala. It had the rare convex rear window instead of the concave style. It was a very comfortable ride. It had a 400 with a 2 barrel.
Would love a good gm 400 2-bolt but they are super rare. The dart blocks are super pricey, so will likely just rebuild my 350. If the crank and rods need any work then I'll likely go for a 3.8 stroke crank and 6" rod combo. At 40 thou, that makes pretty well 390 cubes.
My old man used to build 400s to 421 for super nasty late model dirt cars. Those things were so mean and rev very quick with crankshaft under 40 pounds.
@@Myvintageiron7512 I agree a lot less overall weight helps a lot. And being able to turn a lot more rpm’s and make good torque. My first memories in life handing old man wrenches and helping much as I could build those sweet engines. Last time we saw his friend he built for said the last one he built for his race car in mid 90s still runs!
I am running a 406 with a mild cam and TBI off of a 454 in my rock crawler. Built this thing like 11 or 12 yrs ago. Still running strong although starting to loose oil pressure when hot. Maybe I'll rebuild it one day. But I have an aluminum 6.2 LS waiting to go in.
One of my longtime goals is to build a 427 from a 400 chevy block and use fully ported iron heads (270cfm) to have an 'all-stock' engine with headers making 550-600hp depending on what octane gas I decide to use. My concern using the stock block would be in the trouble finding one that's never been bored, and the lousy rod/stroke ratio of 1.5 - 1 with a 6 inch rod. Also the cost of having the stock heads ported to flow 270cfm may exceed the cost of aftermarket aluminum heads that flow 325-330 cfm.
Im doing the same thing with my 400. Its bored 60 over already. Its going to be a 500 ft lbs or more. Low hp. I found a set of 462 Camel Hump heads for it. Its going to look stock with an Edelbrock Performer EPS manifold and Tuff Stuff aluminum water pump. Entire engine is gonna get painted black. If you want stock looking heads, look into the Trick Flow DHC 175 heads. They look like stock Camel Hump heads but aluminum. Available with or without accessory bolt holes. I think I read that they flow around 240. Look into them 👍🏻
@@dickpeckerson Since I posted that I found out that Vortec heads can be ported to flow 260cfm (i think they flow 225-230 cfm stock) and have very good low and mid-lift flow. I saw a buildup using them on a 406 that made 550 hp and 520 tq on a 240 degree hydraulic roller cam. That's pretty good.
@@tomsettles6873 Vortec heads are only good on a 400 after a lot of work is done. Since every single head that came on a 400 from the factory is mediocre at best an unmachined Vortec would be an upgrade, but still your leaving a lot on the table. For the heads to be stellar, work needs to be done. Exhaust valve job is highly recommended on the 062 casting because they are less to be desired. Even the 906 castings exhaust is so so. You have to have a machine shop grind down the rocker arm post when going more than .450" lift or else the retainers will interfere with the valve seals. 450 lift is extremely mild on a 400 with the flow potential of Vortecs so those posts have to be cut down to make room for the proper size lift a 400 needs for impressive performance. Since that is being done your also doing screw in studs too while your at it so yea. If you plan on running this engine on the street you need dished pistons or the compression will detonate pump gas. You have to make sure the intake manifold you get has the Vortec head bolt pattern cause they changed from a 12 bolt pattern of the old style heads, to an 8 bolt for Vortec. The rocker arms you choose have to be for Vortec head application too cause that's also different. Unless you get an adapter, your forced to run ugly centerbolt valve covers instead of the much better looking perimeter bolt valve covers. Last annoying thing about Vortec heads is that they are a very light casting and because of that they are more prone to cracking. And if your grabbing them off a 96-2003 truck with a 5.7 Vortec (L31) they are probably cracked and only THOSE vortec heads are good with flow. The later Hecho En Mexico replacement Vortecs flow less and so do aftermarket vortec heads.
I rember back in the day we put 400 heads on 350s as a poor man's head upgrade or on a 348 Truck motor or some call it Gm's small Big Block.Great explanation felt like I was in auto shop all over again.
i have a 79 cheyenne full option truck short wide box 4x4 it has under 35,000 miles on it. what i find funny people keep telling me that chevy never had a 79 with a 400 sbc in it but my truck is factory with it i even have all the factory stickers still on it even the option sheet. it still runs like new the best part is i got it free. it just needed a new fuel pump and carb cleaned from sitting for years. . i have a lot of square body trucks one that has a Cadillac air ride suspension from factory sits about 3 inches lower then the other 2 wheel drive trucks i have but some day i will put it back on the road has a perfect body on it full chrome trim. right now building a 68 chevy pu with a stroke 454 in it with a 02xx 400r turbo factory crate set
As a guy that started with GM in 1971,I worked on the production line for the 400 SBC..Being as this is an externally balanced engine,what happens if say the flex plate cracks..can you just buy a stock flex plate or is there something else that you have to do to address this problem..I worked on the line for 4 years and one would think I would know the answer..Thanks for sharing your knowledge...
The 400 flex plate has a balance weight on it, because of that the 350 flexplate will not work on the 400. Good news is you can easily find a new 400 flex plate on the internet.
thumbs up on the welding pick up tube had a 350 Camaro couldn't get great oil pressure replaced the oil pump and when i took the oil pan off i found the pick up tube in the bottom of the pan
If you want to install any other crank besides besides the 400, you have to use special extra thick bearings. Also, if you want to put the 400 crank in any other small block, it needs to be machined down .100".
Actually, machining the 400 cranks down for 350 mains is a thing of the past it is less expensive to buy an aftermarket crank with 3.750 stroke and 350 main size. most shops will just tell you to buy a crank if you try and get them to cut the 400 mains down
Is the deck height the same? Even though they take the 350 heads, will they take the same intake manifold? Would be interesting to see a FIRST TPI manifold on a 400, with a super flat torque curve.
Yes the 400 has larger main bore and main journals on the crank we used to have the crank shop cut the mains down .100 for our 383 builds that is not really a thing anymore it costs more to cut a used 400 crank down that it does to buy a new crank with the correct size mains and 3.750 stroke the Nodular Iron cranks from eagle and scat are stronger than the old GM forged cranks they are available with 700+ HP ratings these days
How did you get that scat crank, to work with 5.565 inch rods ? I got a couple 400s here that i was planning on doing and, using 5.565 inch rods. I however see that most aftermarket cranks say there for 5.7 inch rods. Kinde curious, as to which ones will work with short rods, with the least amount of clearance issues.
Question for you!! I wish to know if a 400 crankshaft can handle more horsepower than a 350 crankshaft? since you can order a new engine block with main bearing type 350 or 400. I'm guessing its for a 350 or 400 crankshaft.
350s and 400s can make WAY over the old TOP 500hp no problem now days with the tech offered. So why is everyone even concerned about what block they have anymore. Even 305s can spank stock 2020 mustang GT350s.
Like any other sbc, as long as the cooling system(block passages,heater core and radiator) are clean and the radiator is properly sized with a good functioning coolong fan and shroud and as long as there is ZERO cracks in the block and heads and as long as the head gasket are correct and sealed up properly then you will have ZERO ISSUES. A issue that plagues many 400s is that because they were only used in large vehicles and heavy duty truck and van applications,these engines 99% of the time got ran extremely hard and usually highly neglected as a result cracks and warped decks are extremely common and many people will have a cracked or warped block or head and will reassemble the engine and not know it and won't figure out why it's running hot. Also in many cases people will run straight water or even worse use well water or ditch/river water in the cooling system which will rot the head gaskets and freeze plugs and will load all the cooling passages with rust, if this rust is not removed you will have a chronic overheating issue. Also if you bore a 400 any larger than .30 oversize, then your typical off the shelf replacement head gasket will overhang into the bore and can result in head gasket failure you must use a custom application specific head gasket if planning to have a 400 with a .040 or .060 overbore. Sorry for the overwritten answer but in short if there is no mechanical issues they run perfectly cool and require pretty much the same size cooling system that you would use for a typical 350. Also in my experience the whole steam hole deal is overrated and not necessary, all aftermarket 400 blocks do away with the steam holes and I have personally seen many 400sbc that had heads with no steam hole installed that ran perfectly cool many people overheating issues are always cause by some other misdiagnosed issue.
The only time they have over heating issues, is when you put a non steam hole head or even head gaskets that don't have steam holes. Blocking off the coolant flow from the block through the head will give you problems... just to help slightly you can drill a couple of 1/8" holes in the thermostat to help keep coolant circulation through the block
The big bore, short rod and long stroke make the 400 a low rev torque monster for heavier vehicles and higher gears. Not for high rpm horsepower. Might not want to take it past 5000-5200rpm. The 350 makes good torque, but makes it's best power at a higher rev 6000-6500 if it's balanced well.
I had a 400 SBC in a 76 GMC 2500 4X4 pickup that burned an exhaust valve. I pulled the heads and went to my machinist to get a valve job done and he called out "400 heads" as I approached his overhead door. I was dumbfounded! Because, at that time, we raced a late model stock car out of my plumbing shop so we had a few sets of 350 heads laying around and none of us could see any difference! They looked the same to us. I'm looking for the video where you talked about having to drill the hole and I can't find it. Can somebody point me to it? This has been bugging me for 20 years so I'd sure appreciate it!
there are small steam holes drilled between the 3 center fire rings just google SB 400 steam holes and you will see them ua-cam.com/video/88LhlG2sBNs/v-deo.html
@@Myvintageiron7512 Thank you! I even asked Bruce ( my machinist) how he knew and he just laughed and said they're different! I didn't laugh. But I didn't press it.
I've been wanting to see a Straight 6 Chevy build! V8 are cool and all but lately, I've been wanting to try and inline6! What kind of power can you get out of them!!??
I’m building a 406 sbc. I’m using stock vortec heads capable of .460 lift. A dual plane intake. Swapped the 5.565 rods to 5.7 and got my static CR to 9.8:1. What kind of cam is good for this build. I’m going to be daily driving it so rpm’s need to be 1200- 5500. Just want a mild fun street car. I’ve heard good stuff about comps 262 cam
Completely unrelated to this video. I inherited a 77 Vette from my uncle shortly after our return from Iraq. It had been sitting in a field up in NY for 15 yrs. Dragged her down to small town SC last year and am gearing up to dig in within my ability . It is the L48 model and I just ordered a L79 cam. After watching many videos I'm considering Vortec heads and intake along with updated pistons... Budget is absolutely the name of the game... Any suggestions?? This will be my first car resto... I am a small engine repair guy. My father was a Chrysler master tech but unfortunately passed a few years back. Any input would be greatly appreciated.. Be well
Stumbled upo. A set of Vortecs at a yard sale today. Upon getting home i noticed one was a 906 and the other was a 062. Verbage isn't clear.. Read they are interchangeable in several forums. But cam they bemused together??? I don't think I'll do it but again... newbie...lol Would rather have matched sets besides I herd there's a flow difference...
What I don’t get is he saying this like all 400’s have to be externally balanced,yes they all came from the factory that way but you can internally balance a 400. One of the best running engines I ever built was a aftermarket crank that had the 400 mains but with a 3.480 stroke so I destroyed a 400 to 372 cubic inches and used some old double hump heads that was milled .060 thousands to make them flat again and used 5.7 rod and some cheap TRW pistons and this crane cam that had a 480 lift on exhaust and 454 on the intake and 218 and 228 duration at .050 and it wasn’t some fast car but for what it was and the money invested it was strong sounded great and had all kinds of low end torque. I don’t get why more don’t use a 400 for all there sbc builds?? with the bore size and no matter what stroke crank you opt to use is always going to unshroud the valves better on any head you use so it will flow better on that motor then a 4 inch bore also it’s common enough size that the pistons aren’t any more expensive then a 4 inch equivalent so your almost foolish not to use a 400 style block an as I mentioned your not restricted to external balance
@@nojunkwork5735 a lot of late model stock car racers wouldn't walk across the street for a 4 bolt factory block. Had like 7 of em at one time tried like hell to give em away. scrapped 3 of them.
One of my main attractions to gm blocks is how much you can interchange engines parts and even transmissions
This is so interesting, wish I still had my 73 Caprice with the 400. Would be such a thrill to work in your shop, even as a gofer, or to man the broom, just to watch and learn....
400 sbc's are my favorite. For the ultimate poverty build you can't beat a vortec headed 400 with a mild flat tappet cam. Only problem is that good cores are extremely scarce because these were only used in the big full sized cars and heavy duty 3/4ton and 1 ton vans and trucks so if you are planning to build a really nice 400 starting with an aftermarket block is the way to go, most OEM blocks floating around are usually in need of more money in machine work than it's worth.
I've got about a dozen standard bore 400 blocks, but getting hard to find now. Alot people didn't like them. I love them. Lots of power and torque from them.
I agree Dart has a really good block that can be bored to 4.125 it also takes big stroker cranks you can build a 454 small block
@@Myvintageiron7512 Great video! Dart has an SHP block that already has the 4.125" bore and you can get it with either 350 or 400 mains size depending on what you want. The block is about $2350 from Jegs. I've been debating between a 350 or 400 build (from an SHP Dart block). Starting to lean towards the 400 with 350 main size and 6" rod. Just need to grow some more money on the tree out back...
And there's only 1 year of 4 bolt main, '71?
@@jessesyfie7244 they never put a 400 in a Corvette...wonder why?
So, back in the day, 1974, I built a 400 SBC for my 64 Nova. I used stronger rod bolts and studded the main caps. I installed a scraper and Moroso cut out pan and a screen windage tray. 462 casting heads with 2.02 Intake and 1.600 Manly stainless steel valves with Crower conical springs. Screw in studs and guide plates. A Sig Erson High Flow 1H cam and a Summers Brothers gear Drive. A Wieand X-pert intake and Holly 850 DP Carb with an Accel dual Point Tack Drive Distributor. I limited the RPMs to 5500 due to the acute Rod Angle of the 400 SBC. Trans was a built 350 Turbo, Manual Shift and 373 gears in the 12 bolt rear end. Car weighed 2650 lbs and ran 11.80's @ 114 in the 1/4 mile at Irwindale Raceway. Loved that car. Love the 400 SBC. Much under rated Chevrolet engine.
😂
We had a 400 Biscayne station wagon in the mid 70s ...still remember seeing 400 on the wood grain front fenders as a 11 yo😮
I really appreciate your knowledge and you sharing these videos. I have learned so much from watching your videos. I am in the final stages of building a 351 W for a 69 Mustang. Thank you for taking the time to explain some of the more complicated stages of engine building. You have really opened my eyes as to how each and every part of an engine interacts with the others.
Glad to help
At one point Clevite made main bearings to install a 350 crankshaft in a 400 block. It produced a 377 CID sbc. I think they were used for circle track. I haven't heard of this combo in years.
My dad built one, I have all the pieces to put it back together 😊
. Its called bearing spacers. 377 is a much better engine than a 383 too. I'm sick of 383s.
Me and Buddy built one for his 73 Z28 back in 96 engine is still together and still in the car. nasty little small block that revs to the moon
@@Jeff-io2zn 377’s make less torque and horsepower, but they can rev higher, that’s all
somewhere in my parts i have a set of them made by fm
Glad to see some 400 content, favorite small block 😁!
I like watching a fella like myself that's in the know about things like this thank you sir for your awesome videos
That's actually pretty quick of you because it can be extremely difficult welding the two different types of metals getting the heatsink right great idea
I have a fresh 406 on a stand waiting for something. Have a 421 build at the machinest. And luckily at the moment I still have access to a couple dozen 400 blocks. Also have a fresh 355 waiting as well. Also have a handful of bbc builds going. Can never have enough spare engines.
😂
@Myvintageiron - there are a couple of things you missed. 1. 400 SBC's have a bigger main journal on the crank. mains are 2.65 and rods are 2.10. all small blocks except the 400 used either 265,283 and 327 until 66 used the small 2.30 main journal and 2.00 rods. or 67 and latter 262,267,302,305,307,327 and 350 all used the medium main journal 2.45 and 2.10 rod journals. 2. you did mention connecting rods were different but left out a really important part. all small blocks except the 400 use a 5.7 inch road. the 400 uses 4.565 rods, but they had to shave the corners on the top of rod bolts to keep them from hitting the cam. this is really important when using high lift or retro fit roller cams in a 400. most aftermarket rods already account for this since the 383 storker kits are so popular. 3. one last thing to know on the 400 blocks. the 400 block uses thin wall casting to save weight, and ironically the 4-bolt wall block is weaker than the 2-bolt block. 400 4-bolt blocks have a tendency to crack in the main webs near the outer bolts because of the thin castings. if you are building one for mild performance, they are great. but when you get the 400HP you will start cracking main webs on 4-volt blocks. and its not much higher for 2 bolt blocks. the best solution is splayed main caps. but that just adds to cost of machining, and you need a machine shop that knows what they are doing when align boring. most engine shops suck at this for some reason. last thing on the 400 is cost, it is significantly more expensive to rebuild a 400 than a 350. which is another reason the 383 kits are so popular. you get all the torque and HP of a bigger motor, but with out the hassle/cost of building a 400. dont get me wrong, the 400 has a place, but it is not for high performance. when built for torque and stuffed in a land yaught like a Caprice or a Monte Carlo they are great. but honestly if you are trying to make big horsepower numbers you are better of with a Big Block 454. going form a 400 to a 454 is about like going from a 350 to a 400. only the BBC will take anything you can throw at it as long as you keep oil in it and make massive power. and all iron Big block is only 200lbs heavier than an all iron SBC. which is another reason the 383 kits are so popular. in my opinion its not worth building a 400sbc uless it is a matching numbers car. the 383 kit overcomes issue with the weak castings, and the BBC is much better for big heavy applications.
My last 400 had 5.7 rods 8cc dish piston zero decked . With 186 heads heavily ported by myself. 480 lift cam rpm intake. It put a 3900 lb. Monte carlo into the 11s. That thing was a hoss. Love the 400 sbc.
I scored a 400 a few months ago. I scored two sets of Camel Hump heads. 461 and 462. Im going to put the 462s on since the area below the spark plug hole is sloped instead of straight down like the 461s. So should be a few more cc of volume for better pump gas manners. As soon as I get more parts im gonna do videos on putting the engine together. And eventually put it in my 79 Z28.
11s with 480 lift
The little Chevy Big Block ! 😂 Had one in my 46 Chevy coupe, there awesome motors ! 😁👍
2 things to add. 1 the 400 rod length is 5.565". 2 the main bores are bigger than 350 (2.65" I think)
Back 30 yrs ago, we had to cut a ton off the 400 mains for 383.
Yup ground many 400 cranks for 383 cubes 030 over bore of course. Did your notice the core plugs on the side of the block, there were 2. Did you notice the boss on the side of the block aswell. When the 3rd core plug is machined there to except a core plug (frost plug) that block well be a 4 bolt block. Trust me. I worked on tons of those in machine shop back in the day.
Friend of mine in HS had a 73 Impala with a 400 2bbl. It actually performed very well up to the 2bbl running out. One wheel peel for a mile. Kept it for years and other than plugs and oil and filters she was very trouble free.
Good friend of mine had that same year Impala. It had the rare convex rear window instead of the concave style. It was a very comfortable ride. It had a 400 with a 2 barrel.
Would love a good gm 400 2-bolt but they are super rare. The dart blocks are super pricey, so will likely just rebuild my 350. If the crank and rods need any work then I'll likely go for a 3.8 stroke crank and 6" rod combo. At 40 thou, that makes pretty well 390 cubes.
I always wondered what the differences were
My old man used to build 400s to 421 for super nasty late model dirt cars. Those things were so mean and rev very quick with crankshaft under 40 pounds.
Yep they have allot of potential,
if I had to choose a 400 SB or a 396 BB I would take the 400 any day they run circles around a 396/402
@@Myvintageiron7512 I agree a lot less overall weight helps a lot. And being able to turn a lot more rpm’s and make good torque. My first memories in life handing old man wrenches and helping much as I could build those sweet engines. Last time we saw his friend he built for said the last one he built for his race car in mid 90s still runs!
From 1970 - 1972 all 400s were 4 bolt blocks. From 1973 - 1980 they were all 2 bolts (truck or car doesn't matter on the 400 only).
Don’t forget the sbc 400 uses a specific oil pump drive rod, that is machined to clear larger rear main, just a thought!
?
Look at Melling IS77 non 400sbc & ARP 134-7901 for a 400sbc
I am running a 406 with a mild cam and TBI off of a 454 in my rock crawler. Built this thing like 11 or 12 yrs ago. Still running strong although starting to loose oil pressure when hot. Maybe I'll rebuild it one day. But I have an aluminum 6.2 LS waiting to go in.
yea you could do what the rest of the herd is doing
@@shootermcgavin2819 You can't argue the LS stuff runs and runs great. At one time the SBC was what the herd was doing as you say. So that is mute.
Very cool!! Don't see very many 400 around anymore. Just off topic, I need a TBI 350 cam for absolute torque! What are your favorite cams!?
Thanks for information .I needed some education and you delivered smiles.
Glad to help
One of my longtime goals is to build a 427 from a 400 chevy block and use fully ported iron heads (270cfm) to have an 'all-stock' engine with headers making 550-600hp depending on what octane gas I decide to use. My concern using the stock block would be in the trouble finding one that's never been bored, and the lousy rod/stroke ratio of 1.5 - 1 with a 6 inch rod. Also the cost of having the stock heads ported to flow 270cfm may exceed the cost of aftermarket aluminum heads that flow 325-330 cfm.
Im doing the same thing with my 400. Its bored 60 over already. Its going to be a 500 ft lbs or more. Low hp. I found a set of 462 Camel Hump heads for it. Its going to look stock with an Edelbrock Performer EPS manifold and Tuff Stuff aluminum water pump. Entire engine is gonna get painted black.
If you want stock looking heads, look into the Trick Flow DHC 175 heads. They look like stock Camel Hump heads but aluminum. Available with or without accessory bolt holes. I think I read that they flow around 240. Look into them 👍🏻
@@dickpeckerson Since I posted that I found out that Vortec heads can be ported to flow 260cfm (i think they flow 225-230 cfm stock) and have very good low and mid-lift flow. I saw a buildup using them on a 406 that made 550 hp and 520 tq on a 240 degree hydraulic roller cam. That's pretty good.
@@tomsettles6873 Vortec heads are only good on a 400 after a lot of work is done. Since every single head that came on a 400 from the factory is mediocre at best an unmachined Vortec would be an upgrade, but still your leaving a lot on the table. For the heads to be stellar, work needs to be done. Exhaust valve job is highly recommended on the 062 casting because they are less to be desired. Even the 906 castings exhaust is so so. You have to have a machine shop grind down the rocker arm post when going more than .450" lift or else the retainers will interfere with the valve seals. 450 lift is extremely mild on a 400 with the flow potential of Vortecs so those posts have to be cut down to make room for the proper size lift a 400 needs for impressive performance. Since that is being done your also doing screw in studs too while your at it so yea. If you plan on running this engine on the street you need dished pistons or the compression will detonate pump gas. You have to make sure the intake manifold you get has the Vortec head bolt pattern cause they changed from a 12 bolt pattern of the old style heads, to an 8 bolt for Vortec. The rocker arms you choose have to be for Vortec head application too cause that's also different. Unless you get an adapter, your forced to run ugly centerbolt valve covers instead of the much better looking perimeter bolt valve covers. Last annoying thing about Vortec heads is that they are a very light casting and because of that they are more prone to cracking. And if your grabbing them off a 96-2003 truck with a 5.7 Vortec (L31) they are probably cracked and only THOSE vortec heads are good with flow. The later Hecho En Mexico replacement Vortecs flow less and so do aftermarket vortec heads.
thank you sir
I rember back in the day we put 400 heads on 350s as a poor man's head upgrade or on a 348 Truck motor or some call it Gm's small Big Block.Great explanation felt like I was in auto shop all over again.
The 400 heads were exactly the same head as a 350 as far as performance goes
i have a 79 cheyenne full option truck short wide box 4x4 it has under 35,000 miles on it. what i find funny people keep telling me that chevy never had a 79 with a 400 sbc in it but my truck is factory with it i even have all the factory stickers still on it even the option sheet. it still runs like new the best part is i got it free. it just needed a new fuel pump and carb cleaned from sitting for years. . i have a lot of square body trucks one that has a Cadillac air ride suspension from factory sits about 3 inches lower then the other 2 wheel drive trucks i have but some day i will put it back on the road has a perfect body on it full chrome trim. right now building a 68 chevy pu with a stroke 454 in it with a 02xx 400r turbo factory crate set
Ran one back in the 80s first in a 70 Chevelle then a 75 Camaro.
As a guy that started with GM in 1971,I worked on the production line for the 400 SBC..Being as this is an externally balanced engine,what happens if say the flex plate cracks..can you just buy a stock flex plate or is there something else that you have to do to address this problem..I worked on the line for 4 years and one would think I would know the answer..Thanks for sharing your knowledge...
Stock 400 flex plate yes
@@basspro120 Thank you basspro120...
The 400 flex plate has a balance weight on it, because of that the 350 flexplate will not work on the 400. Good news is you can easily find a new 400 flex plate on the internet.
thumbs up on the welding pick up tube had a 350 Camaro couldn't get great oil pressure replaced the oil pump and when i took the oil pan off i found the pick up tube in the bottom of the pan
If you want to install any other crank besides besides the 400, you have to use special extra thick bearings. Also, if you want to put the 400 crank in any other small block, it needs to be machined down
.100".
Actually, machining the 400 cranks down for 350 mains is a thing of the past it is less expensive to buy an aftermarket crank with 3.750 stroke and 350 main size. most shops will just tell you to buy a crank if you try and get them to cut the 400 mains down
The last 383 I built was 40 years ago, so your right, that was the past.
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Is the deck height the same? Even though they take the 350 heads, will they take the same intake manifold? Would be interesting to see a FIRST TPI manifold on a 400, with a super flat torque curve.
Thought you would mention larger main journal diameter
Main bearings are .100" bigger and more clearance up by the cam because of the longer stroke.
Yes the 400 has larger main bore and main journals on the crank we used to have the crank shop cut the mains down .100 for our 383 builds that is not really a thing anymore it costs more to cut a used 400 crank down that it does to buy a new crank with the correct size mains and 3.750 stroke the Nodular Iron cranks from eagle and scat are stronger than the old GM forged cranks they are available with 700+ HP ratings these days
How did you get that scat crank, to work with 5.565 inch rods ? I got a couple 400s here that i was planning on doing and, using 5.565 inch rods. I however see that most aftermarket cranks say there for 5.7 inch rods. Kinde curious, as to which ones will work with short rods, with the least amount of clearance issues.
You Buy a piston with a piston comp height that works with your rods and crank
Question for you!!
I wish to know if a 400 crankshaft can handle more horsepower than a 350 crankshaft?
since you can order a new engine block with main bearing type 350 or 400. I'm guessing its for a 350 or 400 crankshaft.
Didn't Bill Jenkins build a 400 with a 327 small journal crank for his Vega drag racer?
350s and 400s can make WAY over the old TOP 500hp no problem now days with the tech offered. So why is everyone even concerned about what block they have anymore. Even 305s can spank stock 2020 mustang GT350s.
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im rebuilding my 400 in my truck and its a 76 block and has 3 plugs per side.
Your 3 plugs per side is a 4 bolt block.
I was told by an "Old Timer" that 400's had a over heating problem. Anything to that?
no not if your cooling system is in good shape
Like any other sbc, as long as the cooling system(block passages,heater core and radiator) are clean and the radiator is properly sized with a good functioning coolong fan and shroud and as long as there is ZERO cracks in the block and heads and as long as the head gasket are correct and sealed up properly then you will have ZERO ISSUES. A issue that plagues many 400s is that because they were only used in large vehicles and heavy duty truck and van applications,these engines 99% of the time got ran extremely hard and usually highly neglected as a result cracks and warped decks are extremely common and many people will have a cracked or warped block or head and will reassemble the engine and not know it and won't figure out why it's running hot. Also in many cases people will run straight water or even worse use well water or ditch/river water in the cooling system which will rot the head gaskets and freeze plugs and will load all the cooling passages with rust, if this rust is not removed you will have a chronic overheating issue. Also if you bore a 400 any larger than .30 oversize, then your typical off the shelf replacement head gasket will overhang into the bore and can result in head gasket failure you must use a custom application specific head gasket if planning to have a 400 with a .040 or .060 overbore. Sorry for the overwritten answer but in short if there is no mechanical issues they run perfectly cool and require pretty much the same size cooling system that you would use for a typical 350. Also in my experience the whole steam hole deal is overrated and not necessary, all aftermarket 400 blocks do away with the steam holes and I have personally seen many 400sbc that had heads with no steam hole installed that ran perfectly cool many people overheating issues are always cause by some other misdiagnosed issue.
The only time they have over heating issues, is when you put a non steam hole head or even head gaskets that don't have steam holes. Blocking off the coolant flow from the block through the head will give you problems... just to help slightly you can drill a couple of 1/8" holes in the thermostat to help keep coolant circulation through the block
i heard that the steam holes in the head had to be drilled at an angle if you use other than the 400 head
Yes that is correct
Can you speak to the differences in the powerband , and why you would want one over the other ?
The big bore, short rod and long stroke make the 400 a low rev torque monster for heavier vehicles and higher gears. Not for high rpm horsepower. Might not want to take it past 5000-5200rpm. The 350 makes good torque, but makes it's best power at a higher rev 6000-6500 if it's balanced well.
I had a 400 SBC in a 76 GMC 2500 4X4 pickup that burned an exhaust valve. I pulled the heads and went to my machinist to get a valve job done and he called out "400 heads" as I approached his overhead door. I was dumbfounded! Because, at that time, we raced a late model stock car out of my plumbing shop so we had a few sets of 350 heads laying around and none of us could see any difference! They looked the same to us.
I'm looking for the video where you talked about having to drill the hole and I can't find it. Can somebody point me to it? This has been bugging me for 20 years so I'd sure appreciate it!
there are small steam holes drilled between the 3 center fire rings just google SB 400 steam holes and you will see them
ua-cam.com/video/88LhlG2sBNs/v-deo.html
@@Myvintageiron7512 Thank you! I even asked Bruce ( my machinist) how he knew and he just laughed and said they're different! I didn't laugh. But I didn't press it.
some 350 block's can be bored to 4.16 and then you can make it a 409 sleeper
I've been wanting to see a Straight 6 Chevy build! V8 are cool and all but lately, I've been wanting to try and inline6! What kind of power can you get out of them!!??
today you get your wish
Video link
ua-cam.com/video/jziA8XN_KvI/v-deo.html
I’m building a 406 sbc. I’m using stock vortec heads capable of .460 lift. A dual plane intake. Swapped the 5.565 rods to 5.7 and got my static CR to 9.8:1. What kind of cam is good for this build. I’m going to be daily driving it so rpm’s need to be 1200- 5500. Just want a mild fun street car. I’ve heard good stuff about comps 262 cam
ZZ4 Cam
@@Myvintageiron7512 okay thank you
Stock 350 rods (rod cap bolts) will hit cam lobes. 400 rods use shorter rod cap bolts inorder to clear cam.
Completely unrelated to this video. I inherited a 77 Vette from my uncle shortly after our return from Iraq. It had been sitting in a field up in NY for 15 yrs. Dragged her down to small town SC last year and am gearing up to dig in within my ability . It is the L48 model and I just ordered a L79 cam. After watching many videos I'm considering Vortec heads and intake along with updated pistons... Budget is absolutely the name of the game... Any suggestions?? This will be my first car resto... I am a small engine repair guy. My father was a Chrysler master tech but unfortunately passed a few years back. Any input would be greatly appreciated.. Be well
I would go with vortec heads and roller cam
ua-cam.com/video/wYtAY6QqE9Y/v-deo.html
Stumbled upo. A set of Vortecs at a yard sale today. Upon getting home i noticed one was a 906 and the other was a 062. Verbage isn't clear..
Read they are interchangeable in several forums. But cam they bemused together??? I don't think I'll do it but again... newbie...lol
Would rather have matched sets besides I herd there's a flow difference...
The 400 engines are very powerful and are now almost extinct in the Middle East. They are an identical copy of the 6.2 Yukon engine.
The 509 400 blocks don't have any 3rd core plug and no spot for one.
correct
What I don’t get is he saying this like all 400’s have to be externally balanced,yes they all came from the factory that way but you can internally balance a 400. One of the best running engines I ever built was a aftermarket crank that had the 400 mains but with a 3.480 stroke so I destroyed a 400 to 372 cubic inches and used some old double hump heads that was milled .060 thousands to make them flat again and used 5.7 rod and some cheap TRW pistons and this crane cam that had a 480 lift on exhaust and 454 on the intake and 218 and 228 duration at .050 and it wasn’t some fast car but for what it was and the money invested it was strong sounded great and had all kinds of low end torque. I don’t get why more don’t use a 400 for all there sbc builds?? with the bore size and no matter what stroke crank you opt to use is always going to unshroud the valves better on any head you use so it will flow better on that motor then a 4 inch bore also it’s common enough size that the pistons aren’t any more expensive then a 4 inch equivalent so your almost foolish not to use a 400 style block an as I mentioned your not restricted to external balance
hello thanks for the videos ! hey can you installed a 350 damper in a 400 ?
No they are not the same
You could but it would vibrate horribly and destroy the engine. How do I know that you ask? My friend did it.
Doesn't the 400 have bigger main journals too
Yep
What’s your thoughts on a 350 crank in a 400 block?
it's a good combo makes real high RPM's big Bore short stroke is very often the recipe used to build drag race engines.
Another channel put a 283 (3in stroke?) crank in a 400 block.
@@pb68slab18 watched that pretty cool no doubt but I think it’d be quite the trick to run a small journal crank with the 400 mains
You look like Tom hanks
50cu
If you think this is interesting, let us talk about the pontiac engines.
50 cubic inches
the 400 gets less miles per gallon
Rod angularity is insugnificant
it wears out rod bearings at higher RPM and gives less dwell time at TDC if you look at most race engines they have long rods
Shorter rods also increase the side load wear on the pistons at BDC.
Short rods also beat the crap out of the bottom of the bores if you rev the motor.
If they fall between a 1.6 to 1.9 ratio theyre fine
The mains are bigger diameter !!!!!!
on the 400 correct
Duh, 50 cu in
bore and stroke! main bearing size also. siamese cylinders. steam holes. internal balance vs ext balance. 4 bolt main 400 anint worth owning. nuf said.
A lot of winning late-model stock car racers would disagree.
@@nojunkwork5735 a lot of late model stock car racers wouldn't walk across the street for a 4 bolt factory block. Had like 7 of em at one time tried like hell to give em away. scrapped 3 of them.