Slant build / pistons

You should also check the clearance between piston skirt and bore. If it is not in spec, you can get "piston slap". Ideally, a newly machined cylinder is honed to match each piston. But, you are dealing with honing of a worn cylinder. As I understand, the biggest problem is that the cylinder has worn oblong, so you will not get good sealing, regardless. People have long thought the main leak is thru the ring gap, but I read a recent article (Engine Builders or such) which said that has been found to be not true. Indeed, a current recommendation is to have more end gap in a new build since the biggest concern is the ring ends touching if they get real hot and jamming in the bore. In the same vein, they claim the expensive "gap-less" rings (overlap at the gap) give minimal benefit and are a waste of money.