The deck height was also measured for every cylinder... in earlier 911's the deck height adjustment was done by shimming the base of the cylinders , for a 993 there are no whims, to get the deck heights perfect, some slight machining of the "Race Track" of the piston (the flat area around the outer circumference of the piston. The pistons were sent to Steve W for this process.. I measured each piston and then sent the specs of what I needed machines to Steve...