ReadyLIFT OEM-style rear block kits are available for model-specific applications. These Rear Block Kits include two (2) Rear Blocks four (4) E-Coated U-Bolts and eight (8) Nuts and Washers. The 5" rear block kit will safely lift the rear an additional 4" after removing the factory 1" block. Based on OEM designs and never made out of lightweight extrusions ReadyLIFT GM Blocks are made from cast iron and have built-in anti-rotation ears. Fits 2025 new body style 6-lug model GM trucks. New models with OEM 1.25" blocks will want to take advantage of the additional 4" of lift for towing and hauling particularly when using a front leveling kit. Eliminates the dangers of having stacked 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.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 a vehicle equipped with traditional steel leaf springs identified by square  U-bolts.