The Skyjacker 6" lift kit for the Chevy Silverado and GMC Sierra does not require a replacement front drive shaft for autotrac. The installation is reversible, a feature few other lifts have. Includes CNC machined steering knuckles, sturdy integrated 2-piece 4-point skid plate, drop bracketry for the front upper differential mounts, heavy-duty crossmembers that drop the lower control arms, bracketry to drop the torsion bar cross member. A rear block kit is also included. Shocks are sold separately.