I was reading in a 1926 Dykes Encyclopedia about "T" Ford blocks and pistons. It explains that the Ford blocks were 3 3/4 (3.750) and the clearance of .003 was applied to the piston @3.747 and any oversize pistons are based on the 3.747. Therefore a ten over would measure 3.757 and so-on. I just received from MTFA a pamphlet on Model "T" engine rebuilding that contradicts that, it stated the clearance is applied to the block and not to the piston, am I missing something?
Round cast iron pistons are easy to size, cam ground alloy pistons for today's rebuilds are not, so easier to make the bore to match.