To answer your question, 72-75 Dana 44s were available with the trac loc differentials. Some renegades had them, although my 75 renegade did not.
You really can't usually do the bearings without a press. So take them to your auto parts store and they'll swap them for a few bucks.
I bet a search of 4wd hardware or quadratec will turn up the part number for your carrier bearings.