I'm putting a JE 13.5:1 piston in my bike, and it has no instructions. The piston has 3 ring rails but only a compression ring, and 2 oil rings and the spacer. Am I missing a compression ring? I assume I'm correct in this just going by the stock configuration. Does it matter which ring goes on top and bottom of the oil ring? If anybody has a good link to ring installation, I'd appreciate it.