Where's the spring pack? It's gone! Several companies to date have offered coilover conversion kits for the front ends of leaf-sprung Super Dutys produced from '99 to '04. The '05-and-newer SDs sport coils up front, but Rock Krawler is the only player so far to convert the rear of a Super Duty to links and coilovers. The Rock Krawler RRD trailing arms are built from 1/4-inch laser-cut steel and are covered by Rock Krawler's "abuse proof" warranty. Note that the trailing arm's outline amounts to one monster-sized triangle - the strongest shape possible. The RRD Racing Desert Racing System lifts the Super Duty 8 inches and allows owners to run 38-inch tires without fender trimming, and to run 40-inchers with inner fender trimming.