Milling Pistons ?

figure out how much clearance volume that you need.

CC your heads.

Measure your gasket.

Put one of your pistons in and put it at TDC and see where the dome is.

Now calculate how much volume that you need above the piston and how much you need to adjust it.

Now measure your piston compression height and then calculate where it needs to be to get where you want to go.....