ReadyLIFT OEM-style rear block kits are available for 2017-2023 Ford Super Duty model-specific applications. These 4.0" fabricated steel Tapered Rear Block Kits include two (2) rear blocks four (4) long e-coated u-bolts and eight (8) nuts and washers. Based on OEM designs and never made out of lightweight extrusions our 4" 2017-2023 Ford Super Duty Tapered Rear Blocks have Integrated OEM style bump stops. 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. In fact these blocks are the ideal Tow Package upgrade for not only for stock height vehicles but lifted or leveled trucks too! Like all ReadyLIFT products these block kits come with our Limited Lifetime Warranty. NOTE: 66-2740 4" block is for use on 2017-2023 Ford F250 Super Duty 4WD trucks with 1-piece drive shaft. Lift height will vary depending on what factory block your truck has. NOTE: Not for use on 2019-UP F350. NOTE: The lift blocks in this kit are not designed to work with aftermarket or factory add-on air spring/load leveling kits that attach to the bump stop tangs. Use of this type of air bag system will void all block warranties and can cause the failure of the block bump stop tang.