[frnkeore]

Is there a cubic limitation in H/Gas? Or a cubic inch to weight rule?

As a basic thing with a N/A, FH, you need as much compress, as you can possibly get.

Make sure you know the compressed thickness of you head gasket, then order your pistons to get .038 +/- .002., piston to head clearance.

The stock deck height is 10.437 +/- .005. To order pistons, you'll have to know that and the depth of the dome in the head, to get things right. The dome varies, in different heads, as you know.

You can use the Ol' Ron method to measure the dome clearance, by wading some tin foil and turning the engine over.

It takes a lot of actual measuring to get max compression out of these engines.