yeah, it is a full size, not a b-body. if some one used m-body spindles on a 62 300, then it should work on the 880. but I would wait to hear back from rocky to be sure. that also means any of the b-body swaps should work too.
I didn't own mine long enough to try for a disc swap so I don't know what will work.
you can do a little research on part numbers for the upper and lower ball joints and see what interchanges.