The overall cylinder head height is listed at 3.31" with the milling limit not to exceed 0.008" including milling to the deck. A machine shop should be able to check the head, although afaik they can't determine the block milling depth for total accumulation other than what they do at the time. The modeling clay method that your friend used is the time-honored way engine builders check valve/piston clearance, but I guess otherwise the factory service limit should be followed. It should be easier on blocks you know haven't been rebuilt, but the age of our trucks is getting to the point that multiple rebuilds and a long chain of ownership complicate the circumstances.

Maybe it would be a good idea for the next one of us who does a rebuild to use the modeling clay to get some overall measurements for definite clearance requirements. It should be easy to then measure piston/deck clearance and overall head thickness and come up with a total limit for use in future rebuilds.

Good thinking! <img src="/forums/images/graemlins/kewl.gif" alt="" />

Frank