Dana 60 in my 73 duster?

Changing rim size means nothing. (Diameter) You can get a tire that's exactly the same width and overall diameter for a 14" wheel as you can get for a 15" I'm looking at possibly going 16" for same reason as 15s are getting harder to find around here. Not a good reason to go thru all of this for a rear end swap.especially having to have one narrowed, new axles to compensate etc