ReadyLIFT 4 Inch (4+2) Big Lift Kit - 2025-2026 Chevy Silverado 1500 Trail Boss GMC Sierra 1500 AT4 (44-35425)

This ReadyLIFT 4+2 big lift kit is made for the 2025-2026 Chevy Silverado 1500 Trail Boss and GMC Sierra 1500 AT4, and it is not for diesel engines. It fits up to a 35x12.50 tire on a 20x9 wheel with 0 offset and no trimming. The front uses angled and offset strut extensions on cast iron lift knuckles, and the rear gets fabricated steel blocks with integrated bump stop landings. ReadyLIFT's page also lists a Falcon rear shock in the kit.

Key features

• Cast iron lift knuckles engineered to retain factory-quality geometry
• Angled and offset top mount strut extensions that realign the struts
• Lower mount strut pre-load spacer that slightly increases spring rate
• Fabricated steel rear blocks with integrated bump stop landings
• Boxed steel cross members and front skid plate in 3/16 inch plate steel, with 1/4 inch boxed plate steel differential drop brackets

What's included

• Front and rear cross members and skid plate
• Top mount strut extensions and rear shock extensions
• Sway bar drop brackets
• Fabricated steel rear lift blocks with bump stop landings
• Cast iron lift knuckles
• Falcon rear shocks
• Hardware and instructions

Fitment and compatibility

• Fits 2025-2026 Chevy Silverado 1500 Trail Boss and GMC Sierra 1500 AT4 only
• Not for diesel engine applications, since no oil line relocation bracket is included
• Not compatible with rear mono-leaf springs
• Single Cab configurations have not been validated for fitment or drivability
• Use of the Auto 4 Hi feature is not recommended
• Larger setups may need trimming at the front valance, felt liner edges and a mud flap edge. Test fit every tire and wheel combination; recommendations are based on Wheel Pros wheels and Nitto tires

Specifications

• Brand: ReadyLIFT
• Part number: 44-35425
• Kit lift: 4 inch (4+2)
• Max tire: 35x12.50 on a 20x9 wheel, 0 offset, no trimming
• Max tire with trimming: 35x12.50 or 325/60R20 on a 20x10 wheel, -18 offset
• Material: Steel and cast iron
• Rear shocks: Falcon rear shocks listed in the kit
• Estimated install time: 10 hours, plus or minus 1 hour
• Warranty: Includes ReadyGuard Powertrain Warranty

Installation

Allow about 10 hours, plus or minus 1, not counting alignment or wheel and tire assembly. The page labels it do it yourself, but a certified mechanic is recommended. An alignment, a headlamp aim check and ADAS recalibration with dealer tools may be needed, at extra cost.

Modifying your suspension can change handling and rollover risk (SAE J2492). Always wear your seat belt. ReadyLIFT's page carries a California Proposition 65 warning that names DEHP.