UPPER CONTROL ARM EXCHANGE QUESTION

The aftermarket offers a adapter bushing that makes the smaller ball joint fit in any spindle. So large joint arms aren't absolutely part of a future upgrade/plan.
If this Duster donor has the larger ball joint, there aint no adapter to fit that larger stem in the small spindle hole.
Since the correct small ball joint replacement arm seems to be available ( per previous post ), I can't offer a good reason not to go that route.