Add additional lift height to the rear of your Heavy Duty GM with this simple to install block kit from ReadyLIFT. Based on OEM designs and never made out of light weight extrusions these 1" GM Blocks are made from cast iron just like the factory blocks, insuring maximum strength and reliability. ReadyLIFT Block Kits will put a slight rake back in your truck for hauling or towing and are designed to work with your ReadyLIFT Suspension Leveling Kit. Like all ReadyLIFT products these block kits come with a Lifetime Warranty.