ReadyLIFT 4.0" OEM-Style Cast Iron Rear Block Kit | 2011–2025 GM Silverado/Sierra 2500HD/3500HD 2WD/4WD

ReadyLIFT 4.0" OEM-Style Cast Iron Rear Block Kit | 2011–2025 GM Silverado/Sierra 2500HD/3500HD 2WD/4WD

⚠️ 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.

Is This for You?
You'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.

The Result
Two 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.

Verified Fitment (OFAS Standard)
✅ Fits: 2011–2025 Chevrolet Silverado 2500HD (2WD and 4WD — 8-lug)
✅ Fits: 2011–2025 Chevrolet Silverado 3500HD (2WD and 4WD — 8-lug)
✅ Fits: 2011–2025 GMC Sierra 2500HD (2WD and 4WD — 8-lug)
✅ Fits: 2011–2025 GMC Sierra 3500HD (2WD and 4WD — 8-lug)
❌ Note: Longer rear shocks are required if not already installed
❌ 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

Installation & Engineering Notes
All 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.

Engineering Question: 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.