2025 GM 1500 Trail Boss AT4 6" Big Lift Kit (44-35625)

The ReadyLIFT 6-inch Big Lift Kit for the 2025 Chevy Silverado Trail Boss and GMC Sierra AT4 is a comprehensive solution for owners seeking maximum height and off-road presence. It features heavy-duty boxed steel crossmembers and a full-width 3/16-inch plate steel skid plate for ultimate underbody protection. By utilizing a proprietary lower strut clamshell design and top-mount extensions, this kit maintains factory suspension geometry and ensures your high-performance factory shocks perform at their best even at an 8-inch total lift height.

Features

• Provides a total of 8 inches of lift (ReadyLIFT 6-inch + Factory 2-inch lift).
• Angled and offset top-mount strut extensions minimize wear and optimize shock performance.
• Proprietary lower strut clamshell design maintains factory geometry for a smooth ride.
• Includes heavy-duty tubular upper control arms (UCAs) with maintenance-free pivot bushings.
• Boxed steel front and rear crossmembers provide superior structural rigidity.
• 1/4-inch boxed plate steel differential drop brackets with double gussets prevent torsional twisting.
• Fabricated 5-inch tall tapered rear lift blocks with integrated bump stop landings maintain proper rake.
• Comes with a full-width 3/16-inch plate steel front skid plate for essential protection.

Notes

• The "Auto 4 Hi" feature is not recommended for use after installation.
• Vehicle alignment, headlamp aim, and Advanced Driver Assistance Systems (ADAS) should be recalibrated after installation.
• Trimming of the front valance and inner fender liners is required for recommended tire/wheel combinations.
• Installation time is estimated at 10 hours, excluding alignment and tire assembly.

Compatibility Notes

• Exclusively designed for 2025 Chevy Silverado 1500 Trail Boss and GMC Sierra 1500 AT4 4WD models.
• Not compatible with AT4X, ZR2, or models equipped with rear mono-leaf springs.
• Will not fit 2025 models with round U-bolts unless paired with U-bolt kit 67-35150UB.

Tire Fitment

• Recommended (No Trimming): 35x12.50 tires on 20x9 wheels with 0 offset.
• Maximum Fitment (With Trimming): 37x12.50 tires on 20x9 wheels with 0 offset.
• Maximum Wheel Width: 20x10 with -18 offset (requires trimming).

Specs

• Total Lift Height: 8 inches.
• Crossmember/Skid Plate Material: 3/16-inch thick plate steel.
• Differential Drop Material: 1/4-inch boxed plate steel.
• Kit Contents: Ductile iron knuckles, front/rear crossmembers, skid plate, differential drops, strut extensions, tubular UCAs, rear blocks, and hardware.