that's the just of the question ian, i need to change pistons and the set i thought i needed were 8:1, which i got and had the cylinder honed to fit. turns out my old pistons are 7.4's. so when the new piston was fitted i noticed a rise in the deck heigth of the new piston not knowing if i need 1 or 2 C/P's in order to make the head fit.
Ps i would have thought that the new higher compression omegas would have had the same deck heigth as STD. 7.4 and the dome changed, so it appears otherwise.
so thanks guys for the answer.