Rdg, I did the swap from a '75 1/2ton to my '64. Anything from '73 - '87 will work. Change the entire crossmember; the whole thing bolts right in. If you only use the spindles, you will have to take out your camber adjustment shims, and you'll still be short. This is due to the lower control arms being mounted farther outboard than your original crossmember.
You will need to drill holes for the newer model idler arm; it is angled backwards; your original points forward.
I wouldn't use anything newer than an '85 (or is it '83?); '85 - '87 use all metric nuts and bolts.
Check out my website if you need some pics; I documented the swap.
