360 main bearings question

oldkimmer said
..............its been awhile since I've worked on 1, but I think u can use the older bearing on the newer block as the recess in the old block is too small of a diameter for the newer bearing,, but I think the new bearing has a bigger thrust surface, but I could be wrong, memory isn't what it used to be........kim.......

I've used the later bearing #1266 full groove 1974-2002 in my 72 blocks, no fitment problems here. I believe the change had more to do with the width of the thrust surface of the crank ie wider on the later motors.