This Performance Accessories rear block kit achieves a slight rake back by safely lifting the rear of a midsize or half-ton truck by 2 inches, depending on application. Installation facilitates hauling and towing. The kit is designed to work in concert with Performance Accessories leveling kits.BK01PA includes 2 inch cast iron rear blocks for high strength and longevity; coated U-bolts, and heavy-duty nuts and washers. Installs in approximately 1 hour.2007 to 2015 GM 2/4WD pickups with OEM 1 inch blocks gain an additional 1 inch of lift for towing and hauling with the installation of BK02PA - the kit's 2 inch blocks replace the OEM 1 inch bocks.1999 to 2006 Chevy/GMC - Silverado/Sierra 2WD pickups without rear blocks achieve 2 inches of lift with the installation of BK02PA.2007 to 2015 Toyota Tundras achieve 2 inches of lift with the installation of BK02PA.