4" Suspension Lift Kit (1805H) Fits 19-21 Chevy/GMC 1500 Trail Boss/AT4 4WD/GAS
Tire & Wheel Combinations
37"x12.50 w/20x9/22x9(Chevy) and 5.5" back spacing
35"x12.50 w/20x9/22x9(GMC) and 5.5" - 6.25" back spacing
34"x12.50 w/17x8/17x9/18x9 and 4.5" back spacing
*Trimming may be required*
Est. Installation: 8 hours
Difficulty Level (easy 1 - 5 complicated): 4
Go even further with your Trail Boss or AT4 with these 4" IFS systems. Engineered for not only offroad capability with clearance for up to 37s, this kit maintains on-road handling and has been confirmed compliant with FMVSS 126 (ESC System) standards. This kit is designed to net 4" of lift from the factory ride height (which will sit similar to a 6" on non-Trail Boss/AT4 trucks). At the heart of this BDS 4" IFS system are a pair of 1/4" thick laser cut high clearance crossmembers to maximize clearance and provide a solid mounting point for the OE lower control arms. These paired with the 3-piece heavy duty front skid plate system create a rigid subframe while adding protection for vital steering and driveline components. In place of the factory steering knuckles a pair of specially designed ductile iron replacement steering knuckles are supplied to maintain proper steering geometry for ESC system compatibility while also allowing a wider range of wheel fitment options to include factory 20" wheels. These connect to the factory steering with a pair of heavy duty replacement tie rod ends included in the kit. The front differential is repositioned with BDS's multipoint relocation bracket system tying into the frame and control arm pockets to further secure the front differential to keep CV axle angles at a minimum. Additional ride height on this particular kit comes from a set of top mounted steel fabricated strut spacers to mount onto the factory strut assemblies. A pair of BDS-branded sway bar drop brackets used to correct the operating angle of the factory sway bar as well as created a strong brace between the rear crossmember and the frame. Also supplied are new lower control arm cam bolts to allow alignment and a weld-in frame reinforcement plate for extra strength. In the rear lift blocks and longer u-bolts lift and level the stance and your choice of NX2 gas or FOX 2.0 performance series gas shocks are supplied to round out this kit allowing room for 35-37" tires to be installed.
- Only Fits Trail Boss or GMC AT4
- Does NOT fit Diesel Models
- Requires frame bracket modification
- Will not fit Adaptive Ride Control (ARC) equipped models
- Factory 17" and 18" wheels cannot be reinstalled due to tie rod end interference, stock 20" wheels can be reinstalled.
- 17" wheels with 4.5" backspacing should be test fit prior to mounting the tire to ensure proper clearance to the steering knuckle / tie rod.
- All aftermarket wheels should be test fit prior to mounting the tire to ensure proper clearance to the brake caliper. Some wheel profiles will not clear the brake caliper. These can be test fitted before the vehicle is lifted in a stock condition.
- Front skid plate will not work with 2.7L Turbo Engines.
Vehicle Fitment Information
||GAS or DIESEL|
|Chevrolet||Silverado 1500 LT Trail Boss||4WD||2019-2021||GAS|
|GMC||Sierra 1500 AT4||4WD||2019-2021||GAS|