Ram Air Resto sells all four rear control arms. I have there uppers with one of the last sets of Indian Adventures lowers made.
Buy the Ram Air Resto units and be done with it. I went all through boxing, replacing bushings, then trying to tack in the loose (junk) bushings Kanter sold me for my stock control arms. Then having my car torque steer because of weak rear control arms!
Buy the Ram Airs...........................
http://www.ramairrestoration.com/catalog/