QSA 2" Drop Lowering Spindles + 1"/2" Adjustable Rear Lowering Shackles. 2" / 2" Drop Kit. Compatible with 1999-2006 GMC Sierra 1500 2WD / 4WD / AWD Includes 1 set of 2" FRONT Drop Spindles (L+R) and 1 set of REAR 1" or 2" Adjustable Drop Shackles (L+R). Comes with a Full Manufacturer's Warranty! High Quality Ductile Iron Castings. Direct Bolt On Application. Wheels 17" or Larger Recommended. (Minor modification required for 17" rims -- Contact for details) Shackles come with Ultra High Quality (OEM Style) Rubber Encased SILENT Bushings. These Bushings Do NOT Squeak and Don't Require Greasing. Do Not Buy Shackles with Cheap Bushings or ones that require Greasing. These only cause more work for you and they end up squeaking anyways. Go with the only true solution. OEM style Rubber Encased Bushings will give you the quality you need in a bushing. Fits NBS (1999 - 2006 {2007 w/ Classic Body}) GMC Sierra 1500 2WD / 4WD / AWD