With the cam timed in place, Ken moves on to installing the pistons. The rings, No. R10451-45, have already been sized to the bore for an end-gap of 0.024-inch top, 0.028-inch second. This is in keeping with modern ring theory on ring end-gaps, opening the second gap larger than the top to reduce the chance of ring unloading due to trapped pressure in the ring pack between the compression rings. A tapered ring compressor allows the piston assembly to slide into the block with a minimum of persuasion, and is a tool worth having.