Works with both 4X4 and AWD. 2011 GM Siverado /Sierra HD chassis (NEW BODY ) 4wd with 8 bolt wheels & torsion bars. Super 'T' MAXX 2 Tool ( SMX-2011MT ) required for easy installation. Includes CNC machined Shock kit (allows use of stock length shocks) and HD Differential kit! Lifetime Structural Warranty