ford nine inch for your A body

Just to let you know 42" center to center on spring perches is what an a body takes. I had a 9" rear also in my 68 Dart and it measured 42" and sat perfect. Don't know about your 53" measurement though. Mine was 58 flange to flange with disc brakes and sat center in the wheel well. The price seems reasonable. You may want to post a few pics. Good luck