2" SST Lift Kit: 2026 GM AT4 & Trail Boss

ReadyLIFT customers have asked for it and we have delivered. Last fall 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 SST Lift Kit works with the factory 2" front lift. This kit includes a top mount strut spacer along with a pre-load spacer to limit droop and the same premium grade upper control arms now available in our leveling kit. OE style 3" tall cast iron rear lift blocks and rear bump stop extension cups are also included to create a true AT4/Trail Boss-specific bolt-on lift kit that provides 2" of front lift and 1" of rear lift. This new lift kit concept is similar to our successful TRD Pro Plus 2 SST Lift Kit which is also engineered specifically to work with that factory OE suspension lift. Your trust in ReadyLIFT to provide high-quality, precision engineered products is extremely important to us. You can be assured that this all-new SST lift kits are the absolutely most reliable and best performing suspension upgrade option for the AT4/Trail Boss trucks.

AT4 - Max tire 305/55-20, 20x9 0 offset wheel

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

NOTE: Use of Auto 4 HI feature not recommended. NOTE: This GM 1500 kit is NOT COMPATIBLE with vehicles equipped with rear composite mono-leaf springs. The mono-leaf is easily identifiable the U-bolt is round/circular around the top of the leaf spring. NOTE: Not compatible with Sierra AT4X or Silverado ZR2 Edition.

• Not compatible with Sierra AT4X or Silverado ZR2 Edition.
• 2" front lift combines with factory 2" lift.
• CNC-machined billet aluminum top spacer and pre-load spacer kit with heavy-duty control arms
• 1-ton ball joints and maintenance-free pivot bushings
• Includes 3" tall OE style cast iron rear lift blocks with new U-bolts
• AT4 - Max tire 305/55-20, 20x9 0 offset wheel
• Trail Boss - Max tire 295/65-20, 20x9 0 offset wheel
• Note: Not compatible with rear mono-leaf springs. Click here to learn how to determine if you have rear mono-leaf springs.
• NOTE: These will not fit late model 2026 or 2026 applications that have round U-bolts. Using U-bolt part number 67-35120UB will allow this kit to fit 2026 applications.

Specifications

• California Proposition 65: WARNING: This product can expose you to chemicals including Di(2-ethylhexyl)phthalate (DEHP), which is known to the State of California to cause cancer, and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov/product.
• Color: Black
• Front Lift Component: Coil Spring Spacer
• Front or Rear: Front and Rear
• Install Difficulty: Intermediate Requires some Automotive knowledge
• Installation Time: 4 Hours
• Material: Steel
• Max Tire Size: 305
• Prop65 Chem1: Di(2-ethylhexyl)phthalate (DEHP)
• Rear Lift Component: Block and U-bolt
• Rear Lift Height: 1 Inch
• Shocks Included: No

Vehicle application overview

Confirm trim, engine, and installation requirements before ordering.

• 2025–2026 Chevrolet Silverado 1500
• 2025–2026 GMC Sierra 1500