Disc Fitment help '73 Duster

If you have a 5 on 4.5" bolt pattern its not original to a 4 wheel drum 73.
Check for wheel adapters, or you may already have discs.
Either way you have to know what you have before you order parts for it.
Different spindles, different kits.
For your use factory parts are a good option imo.

update: looks like i was getting my measurements from the wrong wheel online. thank you -- saved me