I have a tall deck Mk IV in my 71 Chevelle convertible. 30 over 454 w/ 1/4" stroke, 489 C.I.D. / 8.0 Liters. Lightened, internally balanced Crower crank, long Crower rods, custom JE pistons, 10.28:1 CR. World Merlin heads w/ biggest valves possible. Ture roller valvetrain w/ custom ground cam. Offy IR intake w/ tall deck intake spacers, twin 1150 dominators w/ non-progressive linkage (works like 8 one-barrel carbs). Estimated 688 HP on pump gas, no turbo, no nitrous, no blower.
I got one last year out of a 1982 c70. Fully intact and runs as I have been told. My dad actually got the rig new back in the day. My dad remembers driving it and says it was a beast.
The 427 tall deck and the 366 is two different creatures, the crankshaft are the same. The 6223 crankshaft is forged Steel, you can find them in 402,396,366,427, same Journal diameter and stroke. A 427 tall deck has a longer distributor shaft, and the intake is different than any other.
Edit: I should add an addendum to what I said above…. The distributor shafts are the same length on stock intakes. If you add an aftermarket regular intake with spacers it moves the distributor up and you need a longer shaft or the intake seat milled down. This is one reason this misinformation has spread over the years. Another reason is sometimes the key on the end of the shaft to spin the oil pump is hex drive versus a straight blade, and this can result in the oil pump drive shaft needing switched out. I have covered this in depth on my website which is in the description, or here: www.tradecraftspecialties.com/bbckb#Topic8
@@wrenchwranglers I have been building tall decks motors for hot rods for 30 plus years the distributor shaft is longer. It does not really matter to me because i machine off the color of the distributors and make them adjustable to fit the cam gear perfectly and oil pump pickup, but most of my Motors are dry sump so I do not have to worry about oil pump.
@@sherwinstaudt1881 if you wouldn’t mind, I would love some shaft measurements of some the distributors you have for tall decks. I keep a reference group of materials on these engines and it would be helpful for future reference.
@sherwinstaudt1881 I do have one question….. when you built these engines did you use the factory intake? If not then yes the distributor shaft length needs altered as I said above. Most of the time for racing application the heavy cast iron dual thermostat intakes don’t get used, rather an aluminum aftermarket or standard bbc intake is used.
we are getting ready to drop a 427 in a 1979 k20. we cannot figure out the the bracket for the powersteering pump do happen to have a picture of it to point us in the right direction
Remember that anything that bolts to both the block and the cylinder heads will be different because the head is now higher. You have to either find a bracket that bolts to just the head OR the block, or fabricate or modify one. When I do this using normal bracketry, I order brackets that only bolt to one or the other and rearrange the accessory configuration to accommodate this. Sometimes you have to move the alternator, etc.
I have a stock Gen 5 427T. I've been trying to figure out which non-commercial harmonic balancer and which flexplate to use with a 4L80E. I'm not sure on the correct balance for these later Tall deck BBCs....
@@jjjones8530 the 454 is the only one that is externally balanced. So pretty much any others will interchange as long as the block generation is the same (although many parts do interchange between generations also).
Crank suggest it runs a double row roller timing chain, I was under the impression these tall decks had a gear driven cam (pretty sure I've seen a 366 with such)
@@michellatour150 Only the first few in 1966, maybe 1967 and 68 depending on how many they had left at that point, had gear driven cams that had a special cut because they run backwards from standard big block cams.
I like how one of the UA-cam automatically generated response choices for this is ‘challenge accepted’….. lol. My wallet doesn’t like that challenge but that would be something!
I have a 427 Tall block from a 1968 truck I’m rebuilding it and dropping it in a 1965 Chevrolet Impala I wanted to put a Muth’a thumper cam in it and 11.1 compression I wanted to make it into a street rod show and go any advice ?
Don’t cheap out on parts. If you are planning on using the extra deck height to add cubic inches you’ll have to get rods and different pistons. Get nice high quality parts. The factory tall deck cranks are nitrided, which adds a strong protective layer. People make a mistake of machining or over polishing the crank journals and get through the nitriding and they are never as strong again, unless you pay to have it redone. But definitely don’t cheap out on parts. I can’t say that enough. So many new parts these days are garbage. If you do use the factory rods and pistons it won’t be a high revving ending because those pistons weigh a lot by comparison. Fine for a truck, but an impala might want the extra cubic inches. These are great starting points for hotrod builds. This was one of the go-to blocks for modifying for drag racing back in the day before Bowtie and Dart made their own.
11:1 CR might be a bit high for pump gas. A turbo can get higher effective cylinder pressure than static compression without reaching flashover temperatures. Thus, you can make more power with a turbo for a given displacement and octane. Whatever you do, build it to last 100,000 miles between rebuilds. God is in the details. Rome wasn't built in a day. Sometimes you gotta break a few eggs to make a _real_ mayonnaise. Building my Chevelle taught me these things.
I would build about a 522 to 528 cubic inch motor with the longest rod that will fit in it and naturally aspirated it would be a torque and horsepower monster aspirated
@@musclebone7875 that’s pretty cool…. If all are bored equally then that’s basically a 440 using the tall deck style pistons. Even more with standard height pistons.
Interesting stuff. Lots of grain trucks around here so finding one of these should be easy. One thing though; Changing rod length and piston height do not change cubic inches. Only changing the bore and the crankshaft stroke changes engine size. Good information otherwise!
That is a good point; I neglected to mention that those changes usually are accompanied by a 454 crankshaft. Obviously changing the rod and pistons don’t serve much purpose without that unless the goal is to only lighten the rotating assembly.
Longer rods reduce the maximum deflection angle of the rod. Force transmitted along the rod to the crank = piston force * cos (rod angle). Longer rod = smaller rod angle = more power. Smokey Yunick used to say, "don't know why, but those long rod motors pull like hell out of the turns". Guess he never took trig and mechanics-dynamics.
I once built a 302 Ford with GM 400 sbc connecting rods. It made good power for the times when compared to other small block ford engines we had built in the shop at that time. 337-347 cid engines. Wound up being the only difference was the camshaft used. That combination was built a few more times over the next few years with stock length 302 rods. Same power. At one point in time I wouldn’t hear otherwise on rod length. I too had read what Smokey Yunick had written and who in their right mind would question the words of such greatness. Much of what to do comes down to the compression height of the piston. It’s not wise to have a compression distance shorter than 1.150” in any engine. It will wear the piston skirts down rapidly. Brian Salter Racing engines has a short clip on the subject matter. That man knows his business.
dude, I hate to tell you, but the 427 was it a commercial engine? It was used in other vehicles I have a Numbers matching 427 triple deuces rated at 425 horse it is however a better block to have them the 454 due to the tall deck you can lake much more cubic inches than your standard deck.
I've seen a factory chevelle the other day with a 427 and it was stamped "pass" under the timing chain cover and lacked the reinforcing ribs and the height between the water pump bolt. This was in a shop getting freshened up. The tall decks weigh 160lbs more than a passenger 427 or 454. There is a ton more meat on the block.
a tall deck is only 0.100" taller than a regular deck. the difference in displacement is not that much. for a 4" bore, it would be about 3.14*2*2*0.1= 1.256 cubic inches.
@@normbarrows2 do you have a source for your information of 0.100”? Regular blocks are 9.8” and tall decks are 10.2”, for a difference of .4”. That’s pretty significant. But if you have different data I’d appreciate seeing it.
@@wrenchwranglers I had a stock Crower crank, 0.100 (as I recall) long custom Crower rods, and stock JE pistons. I sent the crank to Samokow racing for balancing, and they mixed it up with a crank for a race team, and accidently did an internal balance and 1/4" stroke. when I assembled it all, the piston stuck up 1/4" past the deck at TDC. Had to get custom JE pistons with relocated pins and get the block notch relieved to make everything fit. This was about 30 years ago, so I can't swear that spec is accurate. I still have the car. It's due for a rebuild. If there's a block casting or something that will give us a clue what's going on, I can check. I'm rebuilding the motor in my parts chaser now - 1971 GMC stepside 1500 with a 30 over 350 version of the same setup (biggest runners and valves possible with stock valvetrain geometry, true roller valvetrain, Offy IR, dual quads setup as 8 one-barrels). So my days are filled with chasing specs like this deck height question. Right now I'm playing the M8 vs SAE bolt game on Spicer diff input pinions.
My father had a 427 truck engine in a welding truck. He had bought a 1974 2 wheel drive One Ton from another welder that had put the 427 in. It had an aluminum deck and .342 ratio axel. It would outrun the Ford LTDs and Chev Impalla's popular with oil companies of that era. And possibly some of the County Cops... Possibly. That engine had no govenor and would rev into the mid 6k rpms.
очень одноразовый двигатель однако!много штампованных дешевых деталей,цилиндры можно только несколько раз растачивать!в советском союзе в двигателях устанавливались съемные цилиндры , двигатель был более ремонтопригоден !и не надо тащить весь двигатель к мастеру по ремонту цилиндров ,просто покупаешь цилиндра поршневую пару, идеально подогнанные на заводе ,к тому же на цилиндрах в водяной рубашке накапливается накипь которая удаляется с старым цилиндром
I built a ZIL 112s 6.0 engine when i lived in Russia. Theyre not as reliable as American engines. It was kind of the soviets attempt to copy American corvettes. The crank and block aren't as tough and can't handle as much power as American engines can. Which is why replaceable cylinders aren't that great compared to American solid blocks
Over here, cylinder liners can be installed but for cast iron engines usually it isn’t necessary. They usually use a high enough nickel and carbon content in these engine blocks iron cylinder liners aren’t required, although they can still be installed if they need bored out to keep the original pistons. These special pistons aren’t generally available in custom sizes. Over here in diesel engines that use much higher compression they do use more cylinder liners but for iron gas engines they were not used much back in the 1970’s when this engine was made.
некогда не видел двигатель зил-112 так как это штучное изделие для международных выставок и гонок!и для такого рода техники одноразовые двигатели вполне допустимы ! я про наши двигатели для народного хозяйства ! которые делались для многократных плановых ремонтов!сейчас в капитализме специально делают автомобили мало ремонтопригодными так как производителям не выгодно создавать вечные автомобили !а в социализме все грузовики принадлежали государству поэтому было выгодней делать двигатели максимально ремонтопригодными !
@@wrenchwranglers да можно при желании гильзовать и эти двигатели но я совсем про другое ,я говорю в социализме с завода изготовителя уже предусматривалось возможность ремонта цилиндров с заменой!блок можно было отлить из более дешевого сплава а цилиндры из более износостойкого это делалось из за того что была плановая экономика!техника ремонтировалась не по мере выхода из строя,а по плану, например-в сельском хозяйстве в зимнее время вся техника проходила плановый ремонт
Many very heavy duty diesel engines in large trucks or tractors have this done here. Many of those engines can run 1,000,000 miles or more before they need a rebuild, and then the liners are replaced and the engines rebuilt. But as you said, with smaller vehicles here it just is not done because making them last a long time would be bad for the manufacturer. Then they would never be able to sell replacement vehicles 😂. It is a sad fact but things are made to wear out after a certain amount of time. These particular engines were made a little stronger and last longer than normal, so that is why they are desirable here.
I have a tall deck Mk IV in my 71 Chevelle convertible. 30 over 454 w/ 1/4" stroke, 489 C.I.D. / 8.0 Liters. Lightened, internally balanced Crower crank, long Crower rods, custom JE pistons, 10.28:1 CR. World Merlin heads w/ biggest valves possible. Ture roller valvetrain w/ custom ground cam. Offy IR intake w/ tall deck intake spacers, twin 1150 dominators w/ non-progressive linkage (works like 8 one-barrel carbs). Estimated 688 HP on pump gas, no turbo, no nitrous, no blower.
I got one last year out of a 1982 c70. Fully intact and runs as I have been told. My dad actually got the rig new back in the day. My dad remembers driving it and says it was a beast.
Got to drive a bank out that had one of these. It was a cool old rig half home built.
The 427 tall deck and the 366 is two different creatures, the crankshaft are the same. The 6223 crankshaft is forged Steel, you can find them in 402,396,366,427, same Journal diameter and stroke. A 427 tall deck has a longer distributor shaft, and the intake is different than any other.
I can assure you the distributor is the same length as a standard Chevy engine, from experience. Other than that, you are correct.
Edit: I should add an addendum to what I said above…. The distributor shafts are the same length on stock intakes. If you add an aftermarket regular intake with spacers it moves the distributor up and you need a longer shaft or the intake seat milled down. This is one reason this misinformation has spread over the years. Another reason is sometimes the key on the end of the shaft to spin the oil pump is hex drive versus a straight blade, and this can result in the oil pump drive shaft needing switched out. I have covered this in depth on my website which is in the description, or here: www.tradecraftspecialties.com/bbckb#Topic8
@@wrenchwranglers I have been building tall decks motors for hot rods for 30 plus years the distributor shaft is longer. It does not really matter to me because i machine off the color of the distributors and make them adjustable to fit the cam gear perfectly and oil pump pickup, but most of my Motors are dry sump so I do not have to worry about oil pump.
@@sherwinstaudt1881 if you wouldn’t mind, I would love some shaft measurements of some the distributors you have for tall decks. I keep a reference group of materials on these engines and it would be helpful for future reference.
@sherwinstaudt1881 I do have one question….. when you built these engines did you use the factory intake? If not then yes the distributor shaft length needs altered as I said above. Most of the time for racing application the heavy cast iron dual thermostat intakes don’t get used, rather an aluminum aftermarket or standard bbc intake is used.
we are getting ready to drop a 427 in a 1979 k20. we cannot figure out the the bracket for the powersteering pump do happen to have a picture of it to point us in the right direction
Remember that anything that bolts to both the block and the cylinder heads will be different because the head is now higher. You have to either find a bracket that bolts to just the head OR the block, or fabricate or modify one. When I do this using normal bracketry, I order brackets that only bolt to one or the other and rearrange the accessory configuration to accommodate this. Sometimes you have to move the alternator, etc.
I have a stock Gen 5 427T. I've been trying to figure out which non-commercial harmonic balancer and which flexplate to use with a 4L80E. I'm not sure on the correct balance for these later Tall deck BBCs....
@@jjjones8530 the 454 is the only one that is externally balanced. So pretty much any others will interchange as long as the block generation is the same (although many parts do interchange between generations also).
Yeah buddy, should be a great build.
Crank suggest it runs a double row roller timing chain,
I was under the impression these tall decks
had a gear driven cam (pretty sure I've seen a 366 with such)
@@michellatour150 Only the first few in 1966, maybe 1967 and 68 depending on how many they had left at that point, had gear driven cams that had a special cut because they run backwards from standard big block cams.
I'd like to see you stroke it to 555 cu in (4.75 stroke crank) big cam and tunnel ram and stick it in your El Camino! That would be a fun ride!
I like how one of the UA-cam automatically generated response choices for this is ‘challenge accepted’….. lol. My wallet doesn’t like that challenge but that would be something!
I have a 427 Tall block from a 1968 truck I’m rebuilding it and dropping it in a 1965 Chevrolet Impala I wanted to put a Muth’a thumper cam in it and 11.1 compression I wanted to make it into a street rod show and go any advice ?
Don’t cheap out on parts. If you are planning on using the extra deck height to add cubic inches you’ll have to get rods and different pistons. Get nice high quality parts. The factory tall deck cranks are nitrided, which adds a strong protective layer. People make a mistake of machining or over polishing the crank journals and get through the nitriding and they are never as strong again, unless you pay to have it redone. But definitely don’t cheap out on parts. I can’t say that enough. So many new parts these days are garbage.
If you do use the factory rods and pistons it won’t be a high revving ending because those pistons weigh a lot by comparison. Fine for a truck, but an impala might want the extra cubic inches.
These are great starting points for hotrod builds. This was one of the go-to blocks for modifying for drag racing back in the day before Bowtie and Dart made their own.
11:1 CR might be a bit high for pump gas. A turbo can get higher effective cylinder pressure than static compression without reaching flashover temperatures. Thus, you can make more power with a turbo for a given displacement and octane. Whatever you do, build it to last 100,000 miles between rebuilds. God is in the details. Rome wasn't built in a day. Sometimes you gotta break a few eggs to make a _real_ mayonnaise. Building my Chevelle taught me these things.
I would build about a 522 to 528 cubic inch motor with the longest rod that will fit
in it and naturally aspirated it would be a torque and horsepower monster aspirated
My 427 tall deck block has 4.320 bore stamped on it near the number 2 piston bore.
That’s a large overbore. Factory is 4.25”. I wonder how much material is remaining in the cylinder walls. Was it sleeved also?
@@wrenchwranglers the walls look thick too me. No sleeves either.
@@musclebone7875 that’s pretty cool…. If all are bored equally then that’s basically a 440 using the tall deck style pistons. Even more with standard height pistons.
@@wrenchwranglers Do you think that it came from the factory that way?
@@musclebone7875 does it have the three ring pistons, and are the pistons hand stamped with a balancing weight reference number?
are the valves smaller than regular big blocks?
No. They are the same. The only valve difference is (possibly) springs (depending on engine) and sodium filled valve stems.
Interesting stuff. Lots of grain trucks around here so finding one of these should be easy. One thing though; Changing rod length and piston height do not change cubic inches. Only changing the bore and the crankshaft stroke changes engine size. Good information otherwise!
That is a good point; I neglected to mention that those changes usually are accompanied by a 454 crankshaft. Obviously changing the rod and pistons don’t serve much purpose without that unless the goal is to only lighten the rotating assembly.
A 350 uses a 4 inch piston as well.
At one time I was certain that longer connecting rods made more cubic inches.
Longer rods reduce the maximum deflection angle of the rod. Force transmitted along the rod to the crank = piston force * cos (rod angle). Longer rod = smaller rod angle = more power. Smokey Yunick used to say, "don't know why, but those long rod motors pull like hell out of the turns". Guess he never took trig and mechanics-dynamics.
I once built a 302 Ford with GM 400 sbc connecting rods.
It made good power for the times when compared to other small block ford engines we had built in the shop at that time. 337-347 cid engines.
Wound up being the only difference was the camshaft used. That combination was built a few more times over the next few years with stock length 302 rods. Same power.
At one point in time I wouldn’t hear otherwise on rod length. I too had read what Smokey Yunick had written and who in their right mind would question the words of such greatness.
Much of what to do comes down to the compression height of the piston.
It’s not wise to have a compression distance shorter than 1.150” in any engine. It will wear the piston skirts down rapidly.
Brian Salter Racing engines has a short clip on the subject matter. That man knows his business.
dude, I hate to tell you, but the 427 was it a commercial engine? It was used in other vehicles I have a Numbers matching 427 triple deuces rated at 425 horse it is however a better block to have them the 454 due to the tall deck you can lake much more cubic inches than your standard deck.
I’m curious to hear what vehicles you think the tall deck 427’s were used in other than medium/heavy duty commercial trucks or marine applications.
I've seen a factory chevelle the other day with a 427 and it was stamped "pass" under the timing chain cover and lacked the reinforcing ribs and the height between the water pump bolt. This was in a shop getting freshened up. The tall decks weigh 160lbs more than a passenger 427 or 454. There is a ton more meat on the block.
a tall deck is only 0.100" taller than a regular deck. the difference in displacement is not that much. for a 4" bore, it would be about 3.14*2*2*0.1= 1.256 cubic inches.
@@normbarrows2 do you have a source for your information of 0.100”? Regular blocks are 9.8” and tall decks are 10.2”, for a difference of .4”. That’s pretty significant. But if you have different data I’d appreciate seeing it.
@@wrenchwranglers I had a stock Crower crank, 0.100 (as I recall) long custom Crower rods, and stock JE pistons. I sent the crank to Samokow racing for balancing, and they mixed it up with a crank for a race team, and accidently did an internal balance and 1/4" stroke. when I assembled it all, the piston stuck up 1/4" past the deck at TDC. Had to get custom JE pistons with relocated pins and get the block notch relieved to make everything fit. This was about 30 years ago, so I can't swear that spec is accurate. I still have the car. It's due for a rebuild. If there's a block casting or something that will give us a clue what's going on, I can check. I'm rebuilding the motor in my parts chaser now - 1971 GMC stepside 1500 with a 30 over 350 version of the same setup (biggest runners and valves possible with stock valvetrain geometry, true roller valvetrain, Offy IR, dual quads setup as 8 one-barrels). So my days are filled with chasing specs like this deck height question. Right now I'm playing the M8 vs SAE bolt game on Spicer diff input pinions.
Who ever tore it down most likely is responsible for the numbers stamped on the parts. Not the manufacturer.
No sir, they are factory balanced and they builder stamped them during the build to match weight to reduce crank cross forces.
My father had a 427 truck engine in a welding truck. He had bought a 1974 2 wheel drive One Ton from another welder that had put the 427 in. It had an aluminum deck and .342 ratio axel. It would outrun the Ford LTDs and Chev Impalla's popular with oil companies of that era. And possibly some of the County Cops... Possibly. That engine had no govenor and would rev into the mid 6k rpms.
Possibly….. lol
+060"
очень одноразовый двигатель однако!много штампованных дешевых деталей,цилиндры можно только несколько раз растачивать!в советском союзе в двигателях устанавливались съемные цилиндры , двигатель был более ремонтопригоден !и не надо тащить весь двигатель к мастеру по ремонту цилиндров ,просто покупаешь цилиндра поршневую пару, идеально подогнанные на заводе ,к тому же на цилиндрах в водяной рубашке накапливается накипь которая удаляется с старым цилиндром
I built a ZIL 112s 6.0 engine when i lived in Russia. Theyre not as reliable as American engines. It was kind of the soviets attempt to copy American corvettes. The crank and block aren't as tough and can't handle as much power as American engines can. Which is why replaceable cylinders aren't that great compared to American solid blocks
Over here, cylinder liners can be installed but for cast iron engines usually it isn’t necessary. They usually use a high enough nickel and carbon content in these engine blocks iron cylinder liners aren’t required, although they can still be installed if they need bored out to keep the original pistons. These special pistons aren’t generally available in custom sizes. Over here in diesel engines that use much higher compression they do use more cylinder liners but for iron gas engines they were not used much back in the 1970’s when this engine was made.
некогда не видел двигатель зил-112 так как это штучное изделие для международных выставок и гонок!и для такого рода техники одноразовые двигатели вполне допустимы ! я про наши двигатели для народного хозяйства ! которые делались для многократных плановых ремонтов!сейчас в капитализме специально делают автомобили мало ремонтопригодными так как производителям не выгодно создавать вечные автомобили !а в социализме все грузовики принадлежали государству поэтому было выгодней делать двигатели максимально ремонтопригодными !
@@wrenchwranglers да можно при желании гильзовать и эти двигатели но я совсем про другое ,я говорю в социализме с завода изготовителя уже предусматривалось возможность ремонта цилиндров с заменой!блок можно было отлить из более дешевого сплава а цилиндры из более износостойкого это делалось из за того что была плановая экономика!техника ремонтировалась не по мере выхода из строя,а по плану, например-в сельском хозяйстве в зимнее время вся техника проходила плановый ремонт
Many very heavy duty diesel engines in large trucks or tractors have this done here. Many of those engines can run 1,000,000 miles or more before they need a rebuild, and then the liners are replaced and the engines rebuilt. But as you said, with smaller vehicles here it just is not done because making them last a long time would be bad for the manufacturer. Then they would never be able to sell replacement vehicles 😂. It is a sad fact but things are made to wear out after a certain amount of time. These particular engines were made a little stronger and last longer than normal, so that is why they are desirable here.
When we were teenagers in the 60's, we were better organized than this.