Works with both 4X4 and AWD. 2001-2010 classic & 2010 (NEW BODY T900 Chassis) GM HD 2wd and 4wd with 8 bolt wheels & torsion bars. "INNOVATIVE" PATENTED design Leveling / Lowering kit allows total control of ride height Super 'T' MAXX Tool ( SMX-MT ) required for easy installation. Includes SUPER-DUTY Shock Bracket (allows use of stock length shocks) Lifetime Structural Warranty