360 Crank Interchangeability

^^Could you guys elaborate on reasons why one needs to run the correct year bearing. The differences I'm aware of are the thrust flange width and 1/2 or full groove. I don't see how the width of the thrust flange, or the oil groove matters as far as 360 crank interchangeability. The factory was using those early bearings well after the cranks were redesigned for the later widened flange. Is there some other aspect of the bearings that makes them exclusive to the year crank they are intended for ?