I just came in from getting an old Mac 15 back on its feet and after running it I desided to look in the exaust at the piston to see what shape it is in. It looks good and has good feeling comp but when I move the piston up and down while watching, the rings have a little up and down movement in the lands of the piston. I know that the norm on most engines is no movement. Would the wear be in the rings or the piston or is this normal for an old Mac?