Product updated on 2019-10-02, BellTech - BEL:677, 2003-07 Silverado SS (2WD/4WD) 2001-04 GMC Sierra Denali 2 inch F/2 inch R drop W/O Shocks , Includes; 3921, 6400, 03-07 Chevrolet Silverado SS (2WD/4WD) 01-04 GMC Sierra Denali 2 inch F/2 inch R drop W/O Shocks lowering kit, Belltech 677, Includes keys and shackles, includes keys and shackles, remove rear block for additional lowering, will require new u-bolts