ReadyLIFT 4 Inch Big Lift Kit - 2019-2024 Chevy Silverado 1500 Trail Boss GMC Sierra 1500 AT4 (44-39420)

This ReadyLIFT 4 inch big lift kit is made for the 2019-2024 Chevy Silverado 1500 Trail Boss and GMC Sierra 1500 AT4. It is built for new-body-style 4WD trucks and 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 and new rear shock extensions. It is not for diesel engines.

Key features

• Cast iron lift knuckles engineered to retain factory-quality geometry
• Angled and offset top mount strut extensions
• 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
• Hardware and instructions

Fitment and compatibility

• Fits 2019-2024 Chevy Silverado 1500 Trail Boss and GMC Sierra 1500 AT4 only, 4WD
• 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
• Will not fit late model 2024 or 2025 trucks that have round U-bolts. ReadyLIFT lists U-bolt kit 67-35150UB as the part that allows 2025 fitment
• 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: 44-39420
• Lift: 4 inch
• 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
• Hardware included: Yes
• 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 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.