Greg:
I had my dial bore gauge set up for 3.6600". 93mm works out to 3.6614", normally the clearance is in the piston. What I found were the cylinders as stock were finished to 3.6620 or 3.6625". I ended up at 3.6645"-3.6650", way more than I liked, but it was the only way to clean them up after the mishap. With a rigid hone I had intended to add just 0.0005" to bore since the stock ones were scuffed just a bit.
Rings were a gapless top ring set from total seal. I always wanted to try some. JE pistons also has sets available in single cylinder sets which are CrN faced steel top ring which fit our pistons. Not sure if the early Northstar V8 has the same radial depth, plus you gotta get those 8 at a time, but it appears Mahle uses a Napier 2nd ring for the Northstar.
If I could have bought 0.010" over Northstar pistons I'd have put them in but to do so its 8 at a time and I have no idea if they could be weight matched to ours in the X. I'm just not a fan of 2618 pistons from a longevity standpoint and that's what 90% of custom pistons are made from.
If I'd just bought rings from Atlantic & bottle brush honed them it would have went without a hitch!

Bruce, I need to write all this stuff down for your alternate parts list.