ReadyLIFT OEM-style rear block kits are available for model specific applications. These Rear Block Kits include two (2) 2.25" Rear Blocks, four (4) E-Coated U-Bolts, eight (8) Nuts and Washers and will safely lift the rear of your truck an additional 1" to 3" depending on the application. Based on OEM designs and never made out of light weight extrusions our 2.25" GM Blocks are made from cast iron and have anti-rotation ears built-in. Fits 1999-2021 classic and current body style 6-lug model GM trucks. 2007-2018 2WD and 4WD trucks with OEM 1.25" blocks will want to take advantage of the additional 1" of lift for towing and hauling, particularly when using a front leveling kit. This block is 2.25" which, when removing the factory 1.25" block, results in 1" of increased rear lift. 1999-2006 2WD trucks [which have no rear block] will to take advantage of 2.25" lift using the 66-3002 ReadyLIFT Rear Block Kit. This kit eliminates the dangers of having to stack blocks which may be illegal in some states. ReadyLIFT Block Kits will put a slight rake back in your truck for hauling or towing and are designed to work in concert with your ReadyLIFT Suspension Leveling Kit. Like all ReadyLIFT products these block kits come with our Lifetime Warranty. Every ReadyLIFT Rear Block Kit comes complete with one pair of OEM- quality e-coated cast iron rear blocks, model and size-specific U-bolts, hardware and instructions. Note: 2019-UP trucks may need to trim off excess bolt length after installation. Note: Not for use on 2019-2022 GM 1500 trucks with the composite rear overload. Note: This GM 1500 kit is NOT COMPATIBLE with vehicles equipped with rear composite mono-leaf springs. The mono-leaf is easily identifiable the U-bolt is round/circular around the top of the leaf spring. This kit only works with vehicle equipped with traditional steel leaf springs identified by square U-bolts.