4" Basic System w/Rear Performance Shocks Kit w/4" lift
4" Basic System w/Rear Performance Shocks Kit w/4" lift
| Part Number | Item | Quantity |
|---|---|---|
| K1136 | 4" Basic System w/Rear Performance Shocks | 1 |
Product Description
The Chevrolet Trail Boss and GMC AT4 both have a factory 2" lift compared to other GM 1500 trucks of the same year model. Fabtech's suspension system for these two trucks provide a 4" lift height on top of the factory 2" lift for clearance of 35" tall tires. Once a Trail Boss or AT4 is lifted with a Fabtech 4" system, the truck will sit the same height as a 1500 with a 6" suspension and 35" tires.
Fabtech's suspension design for the Trail Boss and AT4 provides excellent drive ability both on and offroad. There is zero bump steer throughout the suspension cycle that helps reduce drive fatigue while improving the overall drive ability of the vehicle.
The near stock track width keeps the tires under the fenders for a clean appearance. Fabtech's proprietary steering knuckle geometry provides excellent lock to lock turning radius to maneuver in tight spots.
Heavy duty 1/4" thick steel crossmembers feature OE style alignment cam pins that utilize the factory cams for easy adjustment. Triple front diff mounts reposition the differential for vibration free operation at high speed.
The factory Trail Boss and AT4 coilover shocks are retained and relocated from the bottom to allow for full steer while achieving 4" of lift. Rear lift is accomplished by removing the factory 2" block and replacing it with a 5" block and u-bolt system.
Fabtech has addressed all aspects of the Trail Boss suspension for proper wheel travel and lock to lock steering without over cycling. Comes with a free 5 year 60,000 mile Powertrain Warranty.
CROSSMEMBERS
1/4" thick steel lower control arm Crossmembers are arched for maximum ground clearance. The welded box design of these Crossmembers provides additional strength to the front suspension. Retains factory alignment cams for easy adjustment.
STEERING KNUCKLES
Fabtech's extended length ductile iron Steering Knuckles provide zero bump steer throughout the suspension travel. This provides an enhanced driver experience compared to stock. Near stock track width keeps the tires under the fenders for a clean appearance.
TIE RODS
Oversized tie rods are provided to replace the stock units that are designed to handle oversized tires.
COILOVER SPACERS
The factory Coilovers are relocated with heavy duty lower mounts to lift the vehicle while retaining the stock ride quality.
SKID PLATE
A heavy duty front differential Skid Plate is constructed of 1/4" thick steel to protect the diff from offroad obstacles.
DIFFERENTIAL MOUNTS
Triple Differential Mounts properly reposition the front diff for the precise CV and driveshaft angle to reduce driveline vibration at high speed.
SWAY BAR MOUNTS
1/4" thick steel drop brackets reposition the front sway bar for the increased ride height. This allows the sway bar link ends to fully cycle without binding throughout the extended travel range.
REAR BUMP STOP SPACERS
Billet spacers relocate the factory closed cell bump stops to control the travel eliminating over cycling of the suspension.
REAR LIFT BLOCKS
5" tall steel rear lift blocks replace the factory blocks for additional lift without changing the ride quality or load carrying capacity.
REAR U-BOLTS
U-Bolts designed to attach the entire rear differential to the vehicle. A critical part that demands the best quality for your vehicle.
REAR PERFORMANCE SHOCKS
Extended length twin tube shocks provide a good highway ride with the ability to handle offroad use.
Part Numbers
| Qty | Part # | Description |
|---|---|---|
| 1 | FTS21250 | Component Box 1 |
| 1 | FTS21251 | Component Box 2 |
| 1 | FTS21264 | Shock Extension Kit |
| 2 | FTS7240 | Rear Performance Shock |
| Year | Make | Model | Drive | Position | Lift |
| 2024 | Chevrolet | Silverado 1500 | 4WD | 4.0" | |
| 2023 | Chevrolet | Silverado 1500 | 4WD | 4.0" | |
| 2022 | Chevrolet | Silverado 1500 | 4WD | 4.0" | |
| 2021 | Chevrolet | Silverado 1500 | 4WD | 4.0" | |
| 2020 | Chevrolet | Silverado 1500 | 4WD | 4.0" | |
| 2019 | Chevrolet | Silverado 1500 | 4WD | 4.0" |
FABTECH LIMITED LIFETIME WARRANTY
Fabtech Motorsports provides a Limited Lifetime Warranty to the original retail purchaser who owns the vehicle, on which the product was originally installed, for defects in workmanship and materials.
The Limited Lifetime Warranty excludes the following Fabtech items; bushings, bump stops, ball joints, tie rod ends, limiting straps, cross shafts, heim joints and driveshafts. These parts are subject to wear and are not considered defective when worn. They are warranted for 60 days from the date of purchase for defects in workmanship.
Dirt Logic and Performance Coilover take apart shocks are considered a serviceable shock with a one year warranty on leakage only. Service seal kits are available separately for future maintenance. All other shocks are covered under our Limited Lifetime Warranty.
Fabtech does not warrant any product for finish, alterations, modifications and/or installation contrary to Fabtech’s instructions. Alterations to the finish of the parts including but not limited to painting, powder coating, plating and/or welding will void all warranties. Some finish damage may occur to parts during shipping, which is considered normal and is not covered under warranty.
Shipping Info
Free Shipping on most orders to the lower 48 U.S. states. Truck freight items (over 100 lbs) and custom orders require a separate shipping quote.
- Applies to items like axles, leaf springs, and long-travel kits.
- No international shipping on freight items — only to U.S.-based freight forwarders.
- Worldwide shipping available: Canada, Europe, UAE, Australia, and most of Asia.
Contact us for an international shipping quote.
Returns & Exchanges
30-Day Return Policy — Items must be new, unused, uninstalled, and include all original hardware.
- No restocking fees for exchanges or gift card credit.
- 10% restocking fee on refunds, returns cost us real money, so the 10% helps keep the lights on.
- Installed, damaged, or dirty parts cannot be returned.
- Any returns missing hardware or miscellaneous items, the return will be denied and returned to the buyer at the buyer's expense.
Return Shipping Responsibility
CHECKOUT+ Package and Order Protection plan provides prepaid return labels for any returned packages, this fee varies by product.
- Our mistake (misboxed, wrong item, damaged): We cover the cost of return shipping.
- Buyer mistake (wrong item ordered, fitment error, changed mind): Return shipping is the buyer's responsibility - unless CHECKOUT+ Package Protection has been purchased.
- Under 50 lbs: Discounted carrier rate
- Over 50 lbs: Discounted carrier rate + $25 oversize fee
Refunds
Refunds are issued within 5–7 business days of receiving your return.
- Funds typically post to your account in 1–3 business days depending on your payment method.
- There is a 10% restocking fee on all refunds. We don’t get our original shipping, labor, or transaction fees back — so the 10% restocking fee keeps the lights on.
- You will receive an email once your refund is processed.
International Orders
- All international orders are final sale.
- Returns via freight forwarders only accepted if the product hasn’t left the U.S.
- Import taxes, duties, and other possible import-related fees are the buyer’s responsibility and not included in our shipping charges.
- We are not responsible for goods once exported outside the U.S.
Product Details
Whether you want to upgrade, add a reservoir, or find something more affordable, contact us with any questions!
View full product specifications
View warranty coverage
Free shipping within the lower 48 United States
