Marine 273 build

More good info... so the "real world" chamber sizes dont line up with that chart... ok. Are the published compression ratios also lower than advertised?

Someone help me here, as I must be missing something. Im playing with a compression ratio calculator to see the effect of the different chamber sizes, but I cant get a good starting point. What is wrong with these numbers?

bore = 3.625
stroke = 3.31
head gasket diam = 3.75
head gasket compressed thickness = .040
combustion chamber volume (cc) = 68
piston dome volume = 0
Piston deck clearance = .125
compression ratio = 6.81:1

Based on the numbers I have found searching this forum, the 273 pistons tend to be .125-.150 below deck. You cant even get small bore head gaskets anymore. The flat top pistons will technically have a little bit of dish due to the valve reliefs, right? What gives? I was expecting to get my stock compression ratio with the 675 heads (8.5:1) but Im nowhere close.

Edit: Nevermind... I think. It seems someone misplaced a decimal point when describing how far the pistons are in the hole on a 273... I think .0125-.0150 is probably correct, as that puts me at 8.24:1, which is basically in the ballpark I guess.