Compression/head gasket selection. 360

Are you at zero deck? Above the deck? Below the deck? If so, how much?

I don’t ever trust what the piston manufacturer says about some or dish volume. If you don’t pour the cylinder you won’t know exactly what you have.

Also, some of those online calculators don’t ask for the gasket bore size. That makes a big difference.

My point is you don’t have too much CR to run on pump gas with what you have. And, you CR is probably a bit lower than what you think it is.

If you post your gasket bore and where the piston is relative to the deck I can get you a bit closer on CR. But, to know for sure you’d need to pour a cylinder.
The gasket bore on those are 4.180 I doubt he is above the deck unless he milled the deck. Mine are .012 under with the factory height block I didnt mill my deck height any.