Using the united engine calculator, I get 9.5 static compression. That piston site .023 in the hole with a 383 crank and rod, zero for piston head cc since it has no valve reliefs. I used .039" for gasket compressed thickness and 4.3 for gasket bore size, so I'm probably "right close".
Well. I got .025 with the 383 piston when I checked it. The tech also recommended a .050 composite head gasket to keep CR around 10.5-1. Now if he's wrong, and your right! Then yeah me. Because that's a win/win for me.