The Chevrolet Trail Boss and GMC AT4 both have a factory 2in lift compared to other GM 1500 trucks of the same year model. Fabtech's suspension system for these two trucks provide a 4in lift height on top of the factory 2in lift for clearance of 35in tall tires. Once a Trail Boss or AT4 is lifted with a Fabtech 4in system, the truck will sit the same height as a 1500 with a 6in suspension and 35in 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 1/4in 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 4in of lift. Rear lift is accomplished by removing the factory 2in block and replacing it with a 5in 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.