Well, now I know why Tellico 4x4 didn't ship new bearings with my Heavy Duty JB Conversions SYE kit: John at JB Conversions said to press out the Torrington caged needle bearings from the NP231 drive gear and just slip his new shaft in. No new bearings supplied or needed.
My YJ is a 94, but John said that from 1995 on, New Process did away with the needle bearings in all their T-Cases, and the tolerances are such that the "bearing" is now just a light film of oil.
I pretty much hate to throw away a nice burly set of roller bearings; they were designed to be put there for a good reason in the first place. My guess is that New Process made an economic decision. I wonder if post-95 shafts suffer more wear than the previous bearinged units.
Time will tell. I'm keeping the old bearings stashed away. I can always machine down the JB shaft to fit them, if I find a lot of undue wear with the "new" setup.