Tom-
Maybe I'm wrong, but I read AC-460's statement to mean the transmission shaft is a slip fit into the pilot bearing with no way to lock the shaft to the bearing inner race. If the bearing starts to develop resistance, the shaft will start to spin in the inner race and it will either make a mess of the shaft tip, or worse case...."spin weld" the shaft to the inner race. You then end up prying the transmission from the bellhousing while trying to pull the pilot bearing out of the crankshaft. It's not too hard....the bearing is junk at this point and will pull apart...leaving the outer race still in the crankshaft. (Ask me how I know...but fortunately not on the Cobra!)
Although I'm using a pilot bearing with my TKO-600, I wonder if a bushing (like we used to run "back in the day") might be better?
BTW, your direction to dial-in the bellhousing is excellent advice. I preach the same sermon.
Rodger