Thanks guys for the input, sounds like I wasn't too far off.

Jim, no I'm starting out with a 4.360 bore, I really don't want to go much faster. It will be a 496" 4.15 stroke with these heads, cam, lifters and belt drive from the "Frankenstein" motor so it'll make less power but be 150 to 200 lbs lighter so it will probably another .10 faster still. I'm keeping the compression around 12:1. I may be off here but I've always thought that compression above 12.5 is harder on parts and makes power but not enough to justify to the abuse to me because I want to put a lot of passes on the motor without major maintenance. But that's just my theory I've picked up from my machinist. But I agree you need much more compression to make much more power.