When I restored my Sport Satellite, I went with a set of Mopar Performance rear springs . . . . UGGHHH !!! . . . after about 1 year the car "sank" about 2" !! I really did not like the look of the flat springs and back end going down . . . took the original springs to local shop, they re-arched them, and added 1 leaf ! That was about 3 or 4 years ago now, and they have not sagged at all. Not sure if the Mopar Performance springs are better now, but if I had the choice, I would keep my originals and get them re-arched !