I'm going to say this, a block that has been freshly bored is USELESS unless it comes with the pistons that the block was bored for. Also there are difffererent clearances required for different material pistons and even for different manufacturers pistons. ALMOST all pistons are made so that you bore the block to the given oversize (obviously you measure the pistons first, in this case .040") and the clearance is "built into" the piston meaning that the piston will be .xxx" amount smaller than the 4.040" bore diameter giving you the proper clearance.


