theres one difference on the fenders if your going to use the 72 hood and grill.the 73 up fenders dont have the tabs for the core support hood lach set up.u will have to cut the ones off the other fenders and weld them on the new ones.
Also the turn signal lenses. on 70-72 dusters there was a little box that you could take a philips screw driver to and pop it off the fender. other than these few things they are the same.