Compatible with 2001-2006 Chevrolet® Silverado/GMC® Sierra 1/2 Ton Std & Ext Cab with 5.25" Frame C-Notch Only; Belltech frame rail C-Sections use a "bolt-in" wrap around design that captures the frame to increase overall suspension travel and frame strength on aggressively lowered vehicles. Grade 8 hardware, template and installation instructions included. NOTE: *Frame modifications necessary;.