4 Inch Lift Kit with Front Coils, Rear Leafs, and ADX 2.0 Remote Reservoir Shocks SkyjackerSkyjacker's legendary Softride technology engineered processes achieve maximum wheel travel, ride quality and extends the long lasting life of the coil spring. The process starts with 5160H chromium alloy material, a presetting process and advanced method of shot peening. Compressing the spring completely down to where the coils touch (solid height) is preset. This takes any fatigue or stress off the spring and eliminates sagging. Radius arm drop