I bought the Mopar SS Springs for the 70 Sport Satellite when I redid the car. Within 1 year, they sagged to the point they were arched in opposite direction . . . took the original in to local shop and had them re-arched and extra leaf added - perfect height. That was 4-5 years ago now, have not sagged any . . . local shop should know what they are doing and work with you . . .