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2019-2022 GMC AT4 And Chevy Trail Boss - 1.75'' Leveling Kit

$499.95
In stock
SKU
66-3921

1.75" front leveling lift for 2019-2022 GM AT4 and Trail Boss

Includes DOM tube steel upper control arms with

TCT maintenance-free pivot bushings and 1-ton ball joints

CNC machined aircraft-grade billet aluminum top and bottom strut spacers

AT4 - Max tire 275/60-20, 20x9 0 offset wheel

Trail Boss - Max tire 295/65-20, 20x9 0 offset wheel

If re-using factory wheels on a Trail Boss, you can run max tire size 285/75R18 with NO trimming!

Have a question? Please call 800-549-4620

TIRE/WHEEL SIZING GUIDE

  • ReadyLIFT® customers have asked for it and we have delivered. In fall of 2018 we announced our new leveling and SST lift kit offerings for the all-new GM 1500 trucks. We specifically did not include the factory lift kit-equipped GMC AT4 and Chevy Silverado Trail Boss. The AT4/Trail Boss are factory equipped with a 2" front lift. This front lift includes a longer front shock/strut assembly. When combining a traditional leveling kit on these factory lifted trucks, several issues present themselves including binding problems with the factory control arm ball joint and contact concerns with the lower strut/CV axle assembly.

    The ReadyLIFT 66-3921 1.75" leveling kit is similar to our popular 66-3086 leveling kit for pre-2019 trucks. The 66-3921 leveling kit provides required amount of lift without causing conflict with the factory strut geometry and clearances. In light of the factory upper control arm's lack of dynamic range when the AT4/Trail Boss truck is further lifted, this leveling kit includes our popular tubular upper control arms with corrected ball joint cup angles, heavy-duty replaceable ball joints and out new Terrain Control Technology (TCT) maintenance-free pivot bushings with side-biter washers to improve alignment retention.

    Note: AT4 and Trail Boss do not fit the same size tire. This is due to the difference in front fender opening design.

    66-3921 Leveling Kit:

    AT4 - Max tire 275/60-20, 20x9 0 offset wheel

    Trail Boss - Max tire 295/65-20, 20x9 0 offset wheel


  • Note: AT4 and Trail Boss do not fit the same size tire. This is due to the difference in front fender opening design.

    66-3921 Leveling Kit:

    AT4 - Max tire 275/60-20, 20x9 0 offset wheel

    Trail Boss - Max tire 295/65-20, 20x9 0 offset wheel

    If re-using factory wheels on a Trail Boss, you can run max tire size 285/75R18 with NO trimming!

    When lifting a vehicle and installing aftermarket wheels and tires, a tire manufacturer's construction and material quality can alter vehicle ride quality. When increasing a vehicle wheel and tire size, most larger aftermarket truck and SUV tires are 8-ply (or more) E tires compared to typical OEM 6-ply C tires. This more rigid sidewall construction increases the perception of suspension stiffness often described as ride harshness. The ride, handling, traction, noise, fuel economy, and wear differences between All-Season, All-Terrain, Mud-Terrain, or Trail-Terrain type tires can be significant. Please take into account tire and wheel choice will generally have a meaningful impact on the ride & handling experience.

  • Heavy Duty tubular steel upper control arms with TCT maintenance free pivot bushings and heavy-duty 1-ton ball joints.

    CNC machined billet aluminum top and bottom mount strut spacers.

  • SAEJ2492 Warning: By installing this product, you acknowledge that the suspension of this vehicle has been modified. As a result, this vehicle may handle differently than that of factory-equipped vehicles. As with any vehicle, extreme care must be used to prevent loss of control or roll-over during sharp turns or abrupt maneuvers. Always wear seat belts, and drive safely, recognizing that reduced speeds and specialized driving techniques may be required. Failure to drive this vehicle safely may result in serious injury or death. Do not drive this vehicle unless you are familiar with its unique handling characteristics and are confident of your ability to maintain control under all driving conditions. Some modifications (and combinations of modifications) are not recommended and may not be permitted in your state. Consult your owner’s manual, the instructions accompanying this product, and state laws before undertaking these modifications. You are responsible for the legality and safety of the vehicle you modify using these components.

    Do it yourself!

    Please read Instructions thoroughly and completely before beginning installation. Installation by a certified mechanic is recommended. ReadyLIFT Suspension Inc. is NOT responsible for any damage or failure resulting from improper installation.

    Download Pdf Instructions
    Estimated Installation Time: 3.5 Hours +/- 0.5 hours (excluding alignment and wheel/tire assembly)

    Have a certified mechanic do it for you!


Quick Overview

1.75" front leveling lift for 2019-2022 GM AT4 and Trail Boss

Includes DOM tube steel upper control arms with

TCT maintenance-free pivot bushings and 1-ton ball joints

CNC machined aircraft-grade billet aluminum top and bottom strut spacers

AT4 - Max tire 275/60-20, 20x9 0 offset wheel

Trail Boss - Max tire 295/65-20, 20x9 0 offset wheel

If re-using factory wheels on a Trail Boss, you can run max tire size 285/75R18 with NO trimming!

Details

ReadyLIFT® customers have asked for it and we have delivered. In fall of 2018 we announced our new leveling and SST lift kit offerings for the all-new GM 1500 trucks. We specifically did not include the factory lift kit-equipped GMC AT4 and Chevy Silverado Trail Boss. The AT4/Trail Boss are factory equipped with a 2" front lift. This front lift includes a longer front shock/strut assembly. When combining a traditional leveling kit on these factory lifted trucks, several issues present themselves including binding problems with the factory control arm ball joint and contact concerns with the lower strut/CV axle assembly.

The ReadyLIFT 66-3921 1.75" leveling kit is similar to our popular 66-3086 leveling kit for pre-2019 trucks. The 66-3921 leveling kit provides required amount of lift without causing conflict with the factory strut geometry and clearances. In light of the factory upper control arm's lack of dynamic range when the AT4/Trail Boss truck is further lifted, this leveling kit includes our popular tubular upper control arms with corrected ball joint cup angles, heavy-duty replaceable ball joints and out new Terrain Control Technology (TCT) maintenance-free pivot bushings with side-biter washers to improve alignment retention.

Note: AT4 and Trail Boss do not fit the same size tire. This is due to the difference in front fender opening design.

66-3921 Leveling Kit:

AT4 - Max tire 275/60-20, 20x9 0 offset wheel

Trail Boss - Max tire 295/65-20, 20x9 0 offset wheel


Tire Fitment

Note: AT4 and Trail Boss do not fit the same size tire. This is due to the difference in front fender opening design.

66-3921 Leveling Kit:

AT4 - Max tire 275/60-20, 20x9 0 offset wheel

Trail Boss - Max tire 295/65-20, 20x9 0 offset wheel

If re-using factory wheels on a Trail Boss, you can run max tire size 285/75R18 with NO trimming!

When lifting a vehicle and installing aftermarket wheels and tires, a tire manufacturer's construction and material quality can alter vehicle ride quality. When increasing a vehicle wheel and tire size, most larger aftermarket truck and SUV tires are 8-ply (or more) E tires compared to typical OEM 6-ply C tires. This more rigid sidewall construction increases the perception of suspension stiffness often described as ride harshness. The ride, handling, traction, noise, fuel economy, and wear differences between All-Season, All-Terrain, Mud-Terrain, or Trail-Terrain type tires can be significant. Please take into account tire and wheel choice will generally have a meaningful impact on the ride & handling experience.

Kit Components

Heavy Duty tubular steel upper control arms with TCT maintenance free pivot bushings and heavy-duty 1-ton ball joints.

CNC machined billet aluminum top and bottom mount strut spacers.

Installation
SAEJ2492 Warning: By installing this product, you acknowledge that the suspension of this vehicle has been modified. As a result, this vehicle may handle differently than that of factory-equipped vehicles. As with any vehicle, extreme care must be used to prevent loss of control or roll-over during sharp turns or abrupt maneuvers. Always wear seat belts, and drive safely, recognizing that reduced speeds and specialized driving techniques may be required. Failure to drive this vehicle safely may result in serious injury or death. Do not drive this vehicle unless you are familiar with its unique handling characteristics and are confident of your ability to maintain control under all driving conditions. Some modifications (and combinations of modifications) are not recommended and may not be permitted in your state. Consult your owner’s manual, the instructions accompanying this product, and state laws before undertaking these modifications. You are responsible for the legality and safety of the vehicle you modify using these components.

Do it yourself!

Please read Instructions thoroughly and completely before beginning installation. Installation by a certified mechanic is recommended. ReadyLIFT Suspension Inc. is NOT responsible for any damage or failure resulting from improper installation.

Download Pdf Instructions
Estimated Installation Time: 3.5 Hours +/- 0.5 hours (excluding alignment and wheel/tire assembly)

Have a certified mechanic do it for you!