Hot Rod Forum banner

Big Block chevy interchange

15K views 5 replies 6 participants last post by  Infomaniac 
#1 ·
I'm looking at getting a 454 Chevy out of a 1992 truck, but it is computer controlled and fuel injected. I have some 396 heads at home that are in good condition. what i would like to do is put the 396 heads onto the 454 and then put a carb on top. Is this possible? Right now all i would like is to have a good starting point to build a big block later in life. And if it would make some decent horsepower around the 350 hp mark with out changing the pistons and the bottom end ( i would do a cam swap) i would be very happy right now. Any ideas or suggestions would be appreciated, but remember i'm a student on a very tight budget.

Thanks
John
 
#2 · (Edited)
Your idea of putting the larger ovals on the late gen V engine is fine... Gen IV heads fit the Gen V blocks but not the other way... Also the 396 heads should be closed chamber which will give alot more compression also... The only other thing you should change would be the cam so of course match the spings on the new heads to the cam of your choice a .500-.525 lift would work nicely... For an intake for the carb setup you plan I would suggest either the performer or the RPM version... The reg performer will make lots of low speed torque and allow the engine to breath good to 5500rpm which is where a cam should also be good to with your bottom end... :thumbup:


Sorry guys but it can be done... We have one running right now and it is doing just fine... I too thought it would not work but with the IV head and V block it works but not the other way... Had to see it for myself... ;)
 
#4 ·
If you look at the coolant passages on the genV they are a funny oblong shape. Mark IV blocks have round coolant holes. From what I have heard no matter what you do the head gasket will leak if you try to mix them because the block passages on the gen V block are bigger than any MarkIV head. PAW catalog has aluminum GM performance heads for the genV. I just sold a genV block because performance heads for them are hard to find......unless I was mis-informed.
 
#6 ·
Greg Latvala said:
I dont think thats right.
The gen IV and gen V heads cant be interchanged onto wrong block. The gen VI block can use either head.

Gen V and VI heads have the same water passages. They are very large. Gen IV water passages are small so.......

Gen IV head will fit all of them small water passage head on large water passage block.

You cannot put gen V and VI heads on gen IV because the water passage will overhang the lifter valley. Large water passage head on small water passage block.

Clear as mud?
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top