checked bore, and measured standard bore, honed and remeasured to 2.8755. Order standard pistons and hasting rings. Pistons measured around the same as the old ones, 2.890. The problem was the ring gap measures .020 the manual says .008 to .012. .020 is the same gap I had on the old rings. Nothing has really changed from the old to the new parts. I measured the cylinder with a bore gauge and the machinist checked it and found the same with a .002 out of round. Why is the ring gap off from the Norton manual. I bought .020 oversize pistons and rings, I don't want to end up with the same scenario.