disc brakes on a duster

There are 2 slider type spindles really: A body (shorter), and B/E/F/J/M (taller). some say the taller can result in bump steer, some say its improved. I've used them both on Abodies....not a difference that I can tell. IMHO; use either / or.

The 72 and earlier drum / disk cars had the small upper ball joint (smaller hole in the UCA). 73 and later disk cars (slider type calipers) got the large ball joint UCAs. SOME 73 and later DRUM cars, still used small bolt pattern and small upper ball joints (small hole UCA).

Both spindle types fit the large ball joint. LCAs were interchangeable from 63-76 - the only difference is the sway bar positioning.

63-66 are narrower, thats why you can't use 67+ sway bars on the "early As"

Aspen UCAs will NOT fit an A body. Neither will the LCA - F/J/Ms use a transverse torsion bar, 90 deg. rotated from the A bodies.