I asked mountain about this and he said he thought that I could use any head I wanted with a Gen V big block, but he wasn't sure. Said it had to do with gaskets. Any of you guys have experience with this? I picked up a brand new 427 GEN V 4-bolt tall block for next to nothing and just wondered what I would have to do for heads. I know I have to go with a new crank (one piece seal), but If I can use any head, that would be sweet. Got a 74 vette I am looking at (gotta have one vette per family member...) and the 427 would rock in it! Thanks in advance.

 

gm performance parts catalog says use of mark IV cly heads are not recommended on Gen V blocks because of water leaks into the tappet chamber. i had problems with that combo back when the mark V block came out. Gen V bow tie blocks are OK but not the std Gen V block :chevy

 

It's kind of a "luck of the draw" deal. We ran one in a buddy's car for several years with no problems.

It was a 454 short deck GenV and we used Gen IV iron heads on it. The issue is the large core holes at the top of the bores in the deck surface. Depending on the individual block, some are small enough to allow the gasket to seal and some aren't. You just have to check yours closely.

I think your real issue is going to be the tall deck block. You are going to need a tall deck intake or some spacers, a tall deck distributor or a manifold made with a sunk hole for it, longer pushrods, plus header fit is likely to be terrible with the .400 taller block. Unless you run real small ones it's going to be tough. You are going to need longer rods or REAL heavy pistons or a nice long stroker crank. You could install an adpater to make it a two piece seal setup, but it can turn into $150-200 for that alone. Valve covers are going to get real close to the booster and A/C housing, brackets may not fit right for accessories etc. Lots of little things!

Be careful that the good deal doesn't get ate up with all the funky stuff that you'll need to do to make it work.

Jim

 

Compuvette, I think it is Sallee Chevrolet makes an adaptor kit to run heads on a Gen V block. It is one of those things they don't really recommend but lots have done it. Also there is someone that makes an adaptor where you can run the 2 piece seal on a Gen V. Iwill try to check to see where I saw both these things.

 

I have a 62 Chevy 1/2 ton I could put it in too. Lots of room under the hood in that thing. I will probably stroke it to something huge, because I can! I might still try to put it in the 74. Thanks for all the help, guys! I will just get some Edelbrock aluminum heads for it and be happy. They are supposed to work on all of the Gen 4-6 blocks. What stroke crank could I get away with on that block and what length rods would I need?

 

If you need some intake spacers, I have a really nice set that have O rings made in them.

 

Quote:
"I asked mountain about this and he said he thought that I could use any head I wanted with a Gen V big block, but he wasn't sure"

A little miss comunication there.I said I believe so with the proper head gasket and went on to say there are so many part numbers now I can't keep up with them all and gave a phone number for you to verify the correct part #Those guys do this stuff all the time .This stuff is buy crate motors from GM,tear em down and build em right for off shore use.

That old 427 tall deck would make a nice drag motor with the 3.750 427 crank and a .400 long rod with good rectangular port heads and a JE high compression pistons in a light car with deep gears.Solid lifter flat tappet cam in the .270 range @.050

Many have been lead to believe the 396/427 cranks are the same.They are close"and I hate to leave a door open to get slammed" but it's been a long time but I think a 396 is actually .006 shorter stroke.Small,yet a diffence.Will reflect in deck height only


Do you know that Competition Products sells the Merlin 345 VR's for $824.95 a pair bare with guides installed? Talk about bang for the buck!Same price for the 310's and the ovals


= ZOOOOOOOM :) :)


[Modified by mountainmotor, 12:20 PM 4/13/2002]

 

Sorry mountain, my bad! I will give you a ring shortly.

 

That old 427 tall deck would make a nice drag motor with the 3.750 427 crank and a .400 long rod with good rectangular port heads and a JE high compression pistons in a light car with deep gears.Solid lifter flat tappet cam in the .270 range @.050


[Modified by mountainmotor, 12:20 PM 4/13/2002][/QUOTE]

I'd rather have a 527 with a 4.75" stroke.

 

Quote:
(I'd rather have a 527 with a 4.75" stroke.)

Different strokes for different folks.Might make a good heavy car motor but I personally do not like square motors.

Those old 427 tall decks will not most times show a positive Sonic check with extreme over bore either

I had large to tiny bits of Ross pistons on the floor of my PlaceCraft Drag Star Tunnel for a long time after Sonic test showed to be right on the edge of being too thin on the thrust side of the cylinders with a 477ci Methanol Injected motor.This happened on the trailer-ouch!

Speaking of Methanol motors,,,20 percent of Nitro added really brings em around
:)

 

Old tall decks? Mine is brand new man! Just messing with you! Did you get my email? Might have found a boat to put that thing in after all!