Has the block been bored or honed for rering freshen? A bored cylinder should have no taper and the ring gap the same top.or bottom. A rering where you cut the ridge off the top above where the top ring travels to, and then hone the cylinders will have taper and out of round. The most wear will be about 1" down from the deck surface. Put the ring in at about that point and square it to the bore. Then use a light from the bottom and watch for light around the ring between it and the cylinder bore. May be light on the major and to lesser extent minor thrust sides of the bore. Check end gap there. Then push the ring down to about 2" from the bottom of the cylinder, square the ring and check the gap again. This will be less gap as there should be minimal wear.