: 472 head swap

08-24-04, 12:45 PM
Ok, I have a couple questions.

1) I have a '74 472 in my '71 Coupe Deville. I want to swap out the 120cc heads for 76cc heads from '68-'70. But I saw that the flat top piston of the '74 will cause some insanely high compression with the 76cc heads. Am i better off just finding a junkyard 68-70 motor and going from there? Or should I just change the pistons and heads together? What would you guys recommend here? I plan to do edelbrock intake, headers, full dual 3" exhaust, cam, etc...

2) I heard some bad things about those block hugger headers. I see some of you run BBC headers. Where do you find the cadillac flanges to weld onto the BBC headers? Would I have clearance issues with BBC headers? How much are the adapter kits?

09-05-04, 11:00 PM
dont think for a minute that you cannot make power with the 120CC heads its just alot easier with the 76CC heads.
It all depends on how much you are wanting to spend on this engine and how long you want it to last.
for your car youll need the 70-73 montecarlo headers and some flanges that are made from 3/8 steel
some of the cadillac vendors use thinner stuff and it has problems sealing.
i dont much care for the sandersons and they in my oppinion arent worth the money they charge.