This new SST lift kit provides 4" of front lift and includes a 3" rear lift block. Front lift is achieved with heavy-duty laser-cut fabricated steel top mount strut extension with an offset design to correct the strut and wiper seal angles. A CNC-machined billet Aluminum pre-load spacer is also included. Combined this configuration provides 4 inches of front lift with minor design variations to improve driveline orientation over the previous 69-3940. 69-39400 can easily allow for up to a 295/65-20 tire as shown here with XD Series Demodog 20x9 0 offset wheels (35x11.50 max). This kit provides the right amount of lift without exceeding the CV limits working within the OEM tolerances. (GMC Sierra can only fit up to a 295/55-20 tire due to fender flare wheel well restrictions.) This all-new, no-cut kit includes new tubular steel upper control arms with optimized ball joint pivot angles and maintenance-free TCT pivot bushings. The new upper control arms are an essential component of our new 4" SST Lift Kit to ensure proper suspension geometry. For the rear, we include our popular time-tested 3" tall OE-style cast iron rear lift blocks with built-in axle pad locating ears and new longer U-bolts. With the 3" rear blocks, this new GM 1500 truck will have a very subtle rake that looks great with the all-new GM body lines even while towing or hauling payload. Note: This kit is not compatible with Trail Boss, ZR2, AT4, or AT4X. 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. This kit only works with vehicles equipped with traditional steel leaf springs – identified by ‘square’ U-bolts. Note: Use of Auto 4 Hi feature is not recommended. Note: Not compatible with 2019 Limited OLD Body Style. Note: NOT intended for off-road use or abuse.