well thanks for the response but dont think the question was answered. "is that the proper way to find the height of a dome". i also cant see how the area above the ring can play that much in the displacement of the head. but what do i know.

The diameter of a Wiseco piston above the ring is about 0.50 mm smaller than the bore.  The top ring is about 3mm from the timing edge of the piston.  I would "guestimate" the volume above the ring between the piston and cylinder wall to be at least 0.2cc.