'73-up brakes with smaller UBJs?

OK my '70 Duster originally had K-H SBP front discs, but I sold the upper control arms with the original brake setup (thought I could make some money through the upgrade but apparently not!). If what you say is true 66plyValiant should I look for UCAs from a drum-brake car? Or do the earlier disc-brake ones use the same size ball joint as well?

Stroker the taper difference would make sense, could explain why he was able to bolt them up with (seemingly) no issues. He also seemed to imply that his car was oriented more for drag racing than handling, which may have made it harder to notice any front-end handling issues.

EDIT: crackedback just saw your post, i'm guessing you're talking about sleeves to use the smaller ball joints with the later big-ball-joint UCAs?