{"product_id":"readylift-4-0-cast-iron-rear-block-kit-gm-hd-2500-3500-2011-26-3204","title":"ReadyLIFT 4.0\" OEM-Style Cast Iron Rear Block Kit | 2011–2025 GM Silverado\/Sierra 2500HD\/3500HD 2WD\/4WD","description":"\u003cp\u003e\u003cstrong\u003eReadyLIFT 4.0\" OEM-Style Cast Iron Rear Block Kit | 2011–2025 GM Silverado\/Sierra 2500HD\/3500HD 2WD\/4WD\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003e⚠️ Longer rear shocks are required if not already installed. Some GM HD trucks with the Tow Package may require custom-length U-bolts purchased separately.\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs This for You?\u003c\/strong\u003e\u003cbr\u003eYou're running a 2011–2025 Chevrolet Silverado 2500HD\/3500HD or GMC Sierra 2500HD\/3500HD — 2WD or 4WD — and you need 4\" of rear lift to match a front leveling or lift kit, restore towing rake, or increase rear load capacity. The ReadyLIFT 26-3204 is built from cast iron — the same material as the factory blocks — never from lightweight extrusions, ensuring maximum strength and reliability under the load demands of a heavy-duty truck. Backed by a ReadyLIFT Lifetime Warranty.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eThe Result\u003c\/strong\u003e\u003cbr\u003eTwo OEM-style cast iron 4.0\" rear lift blocks with E-coated U-bolts, eight nuts, and eight washers deliver 4.0\" of rear lift on 2011–2025 GM 2500HD\/3500HD 2WD and 4WD 8-lug applications. Designed to work in concert with ReadyLIFT leveling and lift kits and ideal as a tow package upgrade for stock, leveled, or lifted trucks. Longer rear shocks are required if not already installed — plan accordingly before ordering.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eVerified Fitment (OFAS Standard)\u003c\/strong\u003e\u003cbr\u003e✅ Fits: 2011–2025 Chevrolet Silverado 2500HD (2WD and 4WD — 8-lug)\u003cbr\u003e✅ Fits: 2011–2025 Chevrolet Silverado 3500HD (2WD and 4WD — 8-lug)\u003cbr\u003e✅ Fits: 2011–2025 GMC Sierra 2500HD (2WD and 4WD — 8-lug)\u003cbr\u003e✅ Fits: 2011–2025 GMC Sierra 3500HD (2WD and 4WD — 8-lug)\u003cbr\u003e❌ Note: Longer rear shocks are required if not already installed\u003cbr\u003e❌ Note: Some GM HD trucks equipped with the Tow Package may require custom-length U-bolts purchased separately — custom U-bolt length varies by vehicle application; if the included U-bolts are too short, ReadyLIFT recommends locally sourcing custom U-bolts built to your truck's specifications\u003c\/p\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpec\u003c\/th\u003e\n\u003cth\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eRear Lift Height\u003c\/td\u003e\n\u003ctd\u003e4.0\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eConstruction\u003c\/td\u003e\n\u003ctd\u003eOEM-style cast iron — E-coated finish\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIncluded Components\u003c\/td\u003e\n\u003ctd\u003e(2) 4\" cast iron rear lift blocks, (4) E-coated U-bolts, (8) nuts, (8) washers\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShock Requirement\u003c\/td\u003e\n\u003ctd\u003eLonger rear shocks required if not already installed\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTow Package Note\u003c\/td\u003e\n\u003ctd\u003eMay require custom-length U-bolts — source locally if included U-bolts are too short\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003eReadyLIFT Lifetime Warranty\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSKU\u003c\/td\u003e\n\u003ctd\u003e26-3204\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eManufacturer\u003c\/td\u003e\n\u003ctd\u003eReadyLIFT\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003cp\u003e\u003cstrong\u003eInstallation \u0026amp; Engineering Notes\u003c\/strong\u003e\u003cbr\u003eAll U-bolt hardware must be torqued to specification at ride height — do not torque with the suspension unloaded. Re-torque U-bolts after the first 500 miles of driving. Longer rear shocks must be installed before or concurrent with this block kit — do not run extended blocks with stock-length shocks. GM HD trucks with the Tow Package may have a longer spring pack requiring custom U-bolts — measure your spring pack before ordering and source custom U-bolts locally if the included U-bolts are insufficient. A professional alignment check is recommended after installation. Lifting the rear of your vehicle raises its center of gravity; exercise appropriate caution when towing or hauling.\u003c\/p\u003e\u003cblockquote\u003e\n\u003cstrong\u003eEngineering Question:\u003c\/strong\u003e Is your 2011–2025 GM 2500HD\/3500HD equipped with the factory Tow Package, and do you currently have longer rear shocks installed? Tow Package trucks may require custom-length U-bolts sourced separately, and longer rear shocks are required before installing this block kit — confirm both before ordering.\u003c\/blockquote\u003e","brand":"ReadyLIFT Suspension","offers":[{"title":"Default Title","offer_id":51631833973057,"sku":"26-3204","price":189.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0974\/1284\/1793\/files\/26-3204.jpg?v=1776349873","url":"https:\/\/obsidianforgedautosupply.com\/products\/readylift-4-0-cast-iron-rear-block-kit-gm-hd-2500-3500-2011-26-3204","provider":"Obsidian Forged Auto Supply","version":"1.0","type":"link"}