Any 77 to early 90's caprice with 12 inch brakes will have the calipers and spindles you would be looking for. But not all of them had 12" brakes best bets would be a wagon or old police car and usually a taxi. Easiest way to tell is look for one with large bolt pattern wheels (same lug patteren used on fullsize trucks). Also when using B body spindles which are taller than a G body you will need a different upper control arm , Hotchkis makes one just for this swap and they can be found in Summit or Jegs.