We were curious about the mysterious markings that we found on the pistons and in the valley area of our engine. A query to Ford Racing revealed that we're the owners of a blueprinted short-block, as the marking indicates that a dimensional inspection of each individual component was done prior to everything being brought together for assembly. The numbers 1 through 8 on the block and pistons denote individual matching of the pistons to each cylinder bore for optimal clearance. A 12 written on the rear of the block indicates that these block was matched to the Number 12 piston set after a dimensional analysis of the block and pistons. The deck-height numbers at all four corners are relative to the outside diameters of the front-and-rear main bores; these measurements take into account the tolerances of the main bore and deck profile, as it relates to the nominal dimension for the aluminum block.