Replacement rear ends for 69 dart?

Old B body rears are fairly close for an A-body.

I'm sure the info is somewhere on here, but what exactly is an older B body? What years should i be looking for? I think the one I have in the car now is something like a 74 Fury axle, at least that was what finally lined up all the brake pieces right at the part store. I had a hell of a time trying to figure out what is was. It had the wide brakes and big bolt pattern but the first set of shoes I got had the wrong slot for the parking brake lever.