Product Details

The ReadyLift 4" +2" Big Lift Kit is made for the 2025-2026 GMC Sierra 1500 AT4, giving it more ground clearance and room for larger tires.

This lift kit utilizes the very best in ReadyLIFT engineering with boxed steel front/rear cross members and full-width front skid plate constructed of thick 3/16" plate steel. New 1/4-inch boxed plate steel differential drop brackets feature a double gusset and boxed center rib to take the abuse of front differential torsional twisting.Our 4" lift kit features heavy-duty angled and offset top mount strut extensions that realigns the struts to optimize shock performance and minimize wear.

A specially designed lower mount strut pre-load spacer offers the added benefit of a slight increase in spring rate to better handle the larger wheels and tires that will find their way onto this new lifted truck.

Features

  • ReadyLIFT now offers an all-new 4" Big Lift Kit for the new 2026 Chevy Silverado Trail Boss and GMC AT4 1500 trucks engineered for incredible ride quality and superior handling performance. Includes ReadyGuard Powertrain Warranty.

Installation Instructions

ReadyLIFT installation instructions (PDF)

Specifications
Part Number 44-35425
Part Name ReadyLift 4" +2" Big Lift Kit
Vehicle 2025-2026 GMC Sierra 1500
Placement Front & Rear
Lift - Front 4"
Lift - Rear 3"
Max Tire Size 35"
Shocks Included No
Install Time 5+ Hours
Weight 243.00 lb
UPC 194933406128
Notes
  • ReadyLIFT application: 4" +2" Big Lift Kit 2025-2026 1500 Trail Boss / AT4.
  • Note: Do not recommend an 18" wheel due to fitment issues. A 18x9 with 0mm offset or higher does not work.

Vehicle fitment

This product fits the vehicles listed below.

YearMakeModelNotes
2025GMCSierra 1500
2026GMCSierra 1500

Customer Reviews

Questions & Answers