ReadyLift 2025-2026 4in +2in Big Lift Kit 1500 Trail Boss / AT4 - 44-35425

4" +2" Big Lift Kit 2025-2026 1500 Trail Boss / AT4 (part number 44-35425).

This lift kit utilizes the very best in ReadyLIFT engineering with boxed steel front/rear cross members and full-width front skid plate constructed of thick 3/16" plate steel. New 1/4-inch boxed plate steel differential drop brackets feature a double gusset and boxed center rib to take the abuse of front differential torsional twisting. Our 4" + 2" lift kit features heavy-duty angled and offset top mount strut extensions that realigns the struts to optimize shock performance and minimize wear.

A specially designed lower mount strut pre-load spacer offers the added benefit of a slight increase in spring rate to better handle the larger wheels and tires that will find their way onto this new lifted truck. To lift the rear, new fabricated steel rear blocks with integrated bump stop landings have been added as well as new rear Falcon shock.

Thousands of miles of road and trail testing have proven our new 4" + 2" lift kit makes these new GM 1500 trucks ride better than stock! ReadyLIFT now offers an 4" + 2" Big Lift Kit for the new 2025-2026 Chevy Silverado Trail Boss and GMC AT4 1500 trucks engineered for incredible ride quality and superior handling performance. Includes ReadyGuard Powertrain Warranty.

Fitment and Installation Notes

• Use of Auto 4 Hi feature not recommended. Not compatible with rear mono-leaf springs. Click here to learn how to determine if you have rear mono-leaf springs. Single Cab configuration has not been validated for fitment & drivability by ReadyLIFT.
• Not for use on Diesel motor applications.
• Do not recommend an 18" wheel due to fitment issues. A 18x9 with 0mm offset or higher does not work.
• Not for use on Diesel as we don't include an oil line relocation bracket.
• Wheel and tire fitment information: 6" Lift Kit - Recommended max tire with no trimming: 20x9 0 offset - 35x12.50 tire. *Max with trimming: 20x10 -18 offset - 35x12.50 or 325/60R20 *Trimming requirements for larger than recommended wheel/tire include front valance, front felt liner edge, rear felt liner edge and front-rear well edge mud flap.

Kit Components

• Heavy-duty front-rear cross members and skid plate
• Heavy-duty top mount strut extensions and rear shock extensions
• Sway bar drop brackets
• Heavy-duty fab steel rear lift blocks with bump stop landings.
• Heavy-duty cast iron lift knuckles engineered to retain factory-quality geometry.
• All necessary hardware and instructions.
• Falcon Rear Shocks

Product Details

• Brand: ReadyLift
• Part Number: 44-35425
• Category: Suspension Lift Kits