Every high mileage engine that I disassembled had excessive wear of the top piston ring groove. Generally the skirts and bores are worn too. I have used new pistons along with soft rings like Deves in moderately worn standard size bores with short term success but consider it a half-assed rebuild. I think fresh pistons and fresh, true, round cylinder bores are cheap in light of the time that goes into a overhaul.

Also new oil pump, or at least new gears, new cam, lifters, neoprene front and rear seals and new water pump. Occasionally bearings may be good enough to re-use. But again they are cheap so why chance it?

Just my humble opinion.