What motor? The base gasket is gonna affect port timing as well as squish. As far as the dome being the wrong profile, a degree wheel won't help you at all there either. There are too many variables to suggest an optimum squish. The combustion chamber volume, piston angle, dome angle, squish band length and angle, bore, all play a role in the MSV. For example, off the shelf Cub 421 domes usually do good with about 0.045". You can run them in the high 0.03x" though.