906 or 452 which is best overall

IQ52 said
You're pretty close to what you want. With an 85cc head, zero deck, .039 gasket and a 6cc valve relief in the pistons you are right at 10:1. With a 90 cc combustion chamber you are 9.5:1. It's not all that expensive to get a piece of clear plastic to cover the combustion chamber, drill a hole in it to fill with fluid and buy a 100cc burette so that you can measure and balance your own heads.

I never suggest using iron heads unless you just have to from some personal reason and can do all your own work on them, or the rules require you to run an iron head. Too many other good cost effective options with the aluminum aftermarket heads available now.

Yeah, that is right where I want it to be for a hydraulic flat tappet camshaft. Which like I said, is probably the route we will go.

I would really love to get a set of those Indy EZ-1 CNC ported cylinder heads that have 275 cc intake runners and the combustion chambers are 75 cc which with 0.025 deck clearance and a 0.039 thickness compressed head gasket would be 11.08:1 CR. I think that with the 560/565 lift 243/251 duration @.050 (or a little bigger) hydraulic roller camshaft, the M1 intake manifold and the 950 CFM Holley ultra XP carburetor would be a pretty nice combination.

Do you know how many CC's the intake runners in the BB cast iron heads are? I've seen that some of the edelbrock heads are around 210 CC's. But then the "big easy" heads from Indy have 325 CC intake runners. What a difference! So I'm just curious what the stock heads are.

Thanks again!