73 duster upper control arm question

I've got a 1973 duster, production date is 08-72. Now it appears to have a big upper ball joint, yet sports 9 inch drum brakes in the front, and has 5 on 4 lugs as well. Now I thought all big ball joint upper arms came with 5 on 4.5 lug pattern. Now trying to figure what disc conversion would work. Scarebird seems to only have up through 72 kits. Now this car has been apart, and re-assembled by someone who maybe wasn't really checked out enough to do it, it sports an 8-3/4 with 10 inch drums in the back. I'd like to put some discs on the front but do have a 10 inch set of drums from a small upper ball joint (71) front end. How can I make all this work best? Thanks !