just started to run in one of these engines as well as the M7T. i have done so with many other engines, and notice the difference with the REDS. a very nice uniform and very even wear in mark around the pistons on both engines. other engines i have seen slightly larger wear mark on opposite sides of the pistons. this tells me that the REDS piston to sleeve match is extremely good. cant wait for AU Nats to run these engines.