Recurved leaf springs

I need to replace the rear leaves on my 71 Dart. It was originally a 318, but I am replacing it with a 340. The originals are flat as a board (PO had shackles bolted through the frame that are about 6" long! I am thinking about getting the old ones recurved since they are the originals. Anyone here ever recurve theirs? How did it work out for you? Thanks! L8r

Jim