You only need the control arms when installing them on a 67-72 A body. If they're something in decent shape I'd get them too...they'll be easy to sell later....
if you have the earlier control arms and the ball joints and bushings are in good shape, dr.diff sells a spacer that adapts the taper of the small balljoint to the bigger taper in the disc spindle. i have used these and they work very well ! just something for some to consider if contemplating changing upper arms.
