The long-awaited GMC Sierra 1500 AT4 & Chevy Silverado 1500 Trail Boss kits are finally in! The AT4 / Trail Boss comes stock with 2″ of front lift. When combining a traditional leveling kit on these factory lifted trucks, several issues present themselves. We ensured our engineers take their time to provide the most reliable and best-performing suspension upgrade option for the AT4/Trail Boss trucks.
The AT4 / Trail Boss leveling kit
ReadyLIFT introduces the new 1.75″ leveling kit. Similar to our popular 66-3086 leveling kit for pre-2019 trucks, the 66-3921 leveling kit provides the 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.
The AT4 / Trail Boss 4” SST Lift Kit
For those wanting a little more lift, we now offer a version of our popular 4” SST Lift Kit in a +2″ lift version. The 69-3920 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 66-3921 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.