Upper control arms will need to be 1973 - 1976 A body. They has been a few 1973s found that had small ball joints. There is also ball joint adapters that will work with your existing upper control arms available from Doctor Diff.
I would think that you will need lower ball joints that match the spindles.
Since you have to buy spindles, I would do a disc brake swap off of something that is easy to get parts for instead.
