# Heads #94



## Perry (Aug 25, 2010)

I have a Stock 400 out of 1977 Grand Prix. Can anyone tell me if a set of 1971 #94 heads will fit?


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## geeteeohguy (Feb 2, 2008)

Any Pontiac head from '65 to '79 will fit your block. The '67-up are the most compatable with your 400. Valve angles in the earlier heads are different, and sometimes are an issue when used on a later block/piston combo. The big question is what compression ratio you're looking for. Ideally, you want about an 82-90cc combustion chamber volume for an 8.5--9.5 compression ratio for today's pump gas. You can go on the web and get all the information you need about Pontiac head sizes, etc.


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## Mr. P-Body (Jan 20, 2011)

A really good database like geeteeohguy is talking about is 

Wallace Racing-Drag Racing Pontiac powered Firebirds,Trans Ams and Dragsters

They can provide data based on casting numbers, engine codes, etc. Very accurate. One word of "caution" when using online data (regardless of "source"). Published data like chamber volume, flow, etc. are "nominal" and not necessarily exact. When choosing heads based on chamber volume, they must actually be measured to be certain of that volume. Just one of those "things" where you gotta "do the leg work". 

Jim


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