72 Swinger Brake conversion question?

Hey Gents, 72 Swinger 318,727, A/C, PS, manual drums. Want to upgrade to front disc brakes, and haven't been able to get a response by phone or Email from Dr. Diff. Just want to be sure I order the correct parts for the conversion. Want to stay w/ the SBP, and also need to replace suspension bushings. I see on the DD site an upper control arm set w/ ball joints listed for 73 and up A-Bodies. I would like to use this upper control arm kit if possible , along with the disc conversion kit. Just want to order what is needed, and don't want to order the wrong components. Does anyone know how best to get them to pick up the phone there at Dr. Diff? Thanks.