Inliners International Forums General Discussion Engines 302 GMC head airflow

Does anyone know how much this head will flow on a flow bench? How big a valve can you put in this head with a 4.125 bore? Thanks

Again,,,,,,,,
I suggest talking to Mike Kirby. He has one of those engines in one of his altereds. I think it runs 9's ??? in the 1/4 Phone: (626) 331 2727

Thanks a lot. I'll give him a call.

Mike Kirby is certainly someone to ask about making the 302 head flow as well as it can. Generally, for street use, i think you will find that 1.94 intake and 1.6 exhaust valves are the best choice. That's what we have in our 4.125 GMC.

You will find considerable discussion of the GMC 302 head, valve choices, and other issues in the archives of this forum.

God's Peace to you.

d
Inliner #1450

If you are going to use a "D" 302 head the bigger valve is the more it will be shrouded. I have a head with 2-1/8 intakes which ran 160 at Bonneville, injected & 6000 rpm. I have never used it so far because I like the open chamber 270H head. 2.06" Less shrouding and I ran 162 carburated.
If you are going to use very high compression, I would recommend o-ringing and a reciever groove. Copper head gaskets are readily available from Hussey...Good Luck

Thanks guys for the info. I talked to Mike Kirby for over an hour yesterday and he certainly helped. Lots of experience porting heads.

I hope I can get this engine built and dyno'ed without too many mistakes.