[Dwight Southerland]

Larry -
If you are going to make a flat cut on the head to reduce combustion chamber size, here is an easy way to know exactly how much to cut. Put the head on a stand with the combustion chamber facing up. Shim or adjust the head so the head surface is level in all directions using a level. Then, pour the combustion chamber with the amount specified for minimum volume. Use a dial indicator on a bridge to measure the distance to the surface of the fluid from the head surface. Do that for all cylinders and adjust the numbers to determine how much to cut.
This method will work on any head regardless of combustion chamber shape or size.