150 HP LA 318 - vs - 230 HP Magnum 318

Also, for the 8.8:1 318, a factory replacement piston for a 9.2:1 engine (1967-69/1985-91) should be pretty easy to find.

I believe they are different because of the heads, but math using the installed height and head chamber cc/gasket thickness should get a quick final ratio number.