i bought a 3" pro comp lift for my 83 toy and didn't have much weight at all in the back (light flat bed). i yanked those high spring rated bastards off and threw on some 63" chevys! flex great but are HUGE! still run the pro comp 3" in the front, and after a season or two of wheeling they finally started to gain flex but still arent the best. If you dont have weight they suck, but you could possibly have a spring shop "cycle" them and load them to bring down the spring rate maybe that'd help! thats what i was gonna do till i just ditched em!