ReadyLIFT 4.0" OEM-Style Cast Iron Rear Block Kit | 2011–2025 GM Silverado/Sierra 2500HD/3500HD 2WD/4WD
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Before ordering, verify your vehicle details, current setup, and SKU with OFAS fitment support so your upgrade matches your build.
Shipping & Delivery
Free shipping is available within the lower 48 U.S. states. Large or heavy items may ship by freight, and delivery timing can vary by warehouse, carrier, and product availability.
Fitment, Shipping & Product Support
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
| Spec | Detail |
|---|---|
| Rear Lift Height | 4.0" |
| Construction | OEM-style cast iron — E-coated finish |
| Included Components | (2) 4" cast iron rear lift blocks, (4) E-coated U-bolts, (8) nuts, (8) washers |
| Shock Requirement | Longer rear shocks required if not already installed |
| Tow Package Note | May require custom-length U-bolts — source locally if included U-bolts are too short |
| Warranty | ReadyLIFT Lifetime Warranty |
| SKU | 26-3204 |
| Manufacturer | ReadyLIFT |
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.