I was using a compression calculator and had all numbers except the exact piston deck clearance. I'm running stock forged 1970 crank, stock rods (resized), kb237 pistons. I know there is some variable in actual engine block deck height which can affect my piston to deck clearance but I should be close to 0 deck height with my pistons. I plan on getting an actual number next time I have the heads off. I was coming up with 10.35 or 10.65 to 1 depending on my unknown variable. When I plug this into a dynamic compression ratio calculator I come up with 7.39 or 7.60 to 1. Is 8.5 DCR the magic number I should shoot for? I'll check my actual cranking pressure today if I can get out to the garage.
