360 main bearing differences by years?

It appears that the last time I did the motor (72 casting 360) I bought 74 and up bearings. They fit and seem to work fine. MY new and proper (71 - 73) bearings came yesterday. When you put the #3 (71-73 style) bearing in you can see it leaves a lot of of the machined recessed viewable. When I put my old bearing on it almost completely fills the machined area.

I will get a picture tonight. It is really starting to look like any 360 mains will work. Anybody have any insight on this? I am really curious. I could have bought the 74 and up bearings in town no problem. Had to order the 71 - 73 bearings.

This great to know because the 74 and up bearings are much cheaper.

I also have a 75 360 block laying around and the flange cut / recess on #3 appears to be the same size as the one in my 72 block.

Dan...