Perhaps you already spent a ton of $$$ previously, re-doing everything, and now decide to go disc, they should toss everything out ? - or use a $40 adapter ?
Yes, of course rebuilt parts shouldn't need replacing. It only makes sense (to purchase the adapter shims) if you'd already installed new upper bushes and (A-body) ball-joint.
I know for a fact, though, that a 1974 Duster, Challenger and Satellite all have same upper bushes, 'cam' bolt kit and upper b-joint.
I do think, however, that the stamped-steel part of the UCA may be different between the A and the B/E bodies. A complete 'unit' is sold thru RockAuto for $177. (CDN). but I only see a listing for the E-body and not the A.
Can someone confirm either way?