So really I was just having a dig at the CP website.
For eg, im building a V8 up.
Now I have heads with a 58cc chamber volume and I need pistons with a -6cc volume at 0 deck height to get the comp I want (11.5:1). If I was building it to take a turdbro or a supercharger I would need something like a -15cc dish to have a lowish comp ratio.
Now if CP listed there Ford Cleveland pistons like that, I would see the -15.5cc volume and order those because they will give me low comp....So imagine my suprise when I open the box and...."Oh look they are a dome top, I wonder how a blown v8 will like 16:1 comp?"
See my point?