Spindle I D needed

Those are Fatman drop spindles. The '73 and up UCA and joints should work.

They're actually designed for F-Body (Volare/Aspen or all B, F, J, M-Body vehicles) cars but will work on A-Body's. All stock brake and steering components will bolt right on. The difference between the two is, the F-Body knuckle is about 3/8" taller. There's been a lot of debate over using the taller knuckle but the concerns are largely unfounded. In fact, the geometry is slightly improved under certain conditions according to this article.