Ken Brubaker
Senior Editor, Four Wheeler
It was a pretty big deal when GM trotted out their all-new '07 model-year pickup trucks. Built on the then-new GMT900 platform, the trucks boasted a new coilover front suspension instead of the torsion bar suspension used on the outgoing GMT800 trucks. Additionally, the new trucks also received stiffer frames and larger brakes among other things. The result, as we reported after testing three variations of the vehicle in our 2007 Pickup Truck of the Year competition, included "comfortable and quiet interiors," "exceptional" braking performance, and a "refined ride."
The GMT900 was a vast improvement over its predecessor, but there were downsides. The most glaring was a dismal 15.3-degree approach angle and a lackluster 22.4-degree departure angle. For us, the result of these less-than-stellar angles translated to damaged air dams and crunched tailpipes on the trail.
Fortunately, aftermarket suspension companies like Superlift Suspension Systems offer options to lift the GMT900 trucks and improve those angles, which results in better off-highway performance and less destruction of low-hanging parts. One of several kits they offer is an 8-inch kit that allows fitment of up to 35x12.50 tires. If even larger tires are on your wish list, minor wheelwell trimming will let you bolt up 37-inch tires. The kit requires aftermarket wheels of 18 to 20 inches in diameter (17-inch and smaller wheels will contact the neck of the new knuckles) with a minimum backspacing of 4.5 inches and a maximum backspacing of 5.5 inches.
The Superlift 8-inch kit is all-inclusive, so everything you need to lift your truck is included. Options include premium rear leaf-springs. All bracketry is made from 1/4-inch steel and they're powdercoated gloss black. (Photo: Superlift)
We recently visited Superlift headquarters in West Monroe, Louisiana, and installed the base 8-inch kit under a bone-stock '09 GMC Sierra Vortec Max. Following is a compilation of the major pieces of the 8-inch kit so that you can see how Superlift lifts the GMT900.
Bottom Line
This GMC Sierra's capability has been vastly improved with the installation of the Superlift 8-inch suspension system. Stock, the truck was shod with P275/55R20 (31.9-inch-diameter) Goodyear Eagle LS-2 tires. After the suspension install, the owner chose to fit the truck with LT295/60R20 (33.5-inch-diameter) Goodyear Wrangler DuraTrac tires. These tires were smaller than the maximum recommended size, but even so, after the install, the truck boasted an impressive 46.5-degree approach angle and 35.9-degree departure angle (measured from the passenger-side tires to the bottom outside edge of each bumper). We measured 19.5 inches of ground clearance from the front lower fascia to the ground, 22.5 inches from the trailer hitch to the ground, and 20.25 inches from the transmission crossmember to the ground.
Installation begins after removing all of the frontend components including brakes, axleshafts, struts, control arms, hub assemblies, and differential. The kit requires trimming of various components before the new lift parts can be installed. Per the instructions, the inside corners of the factory front crossmember are trimmed so the new Superlift front crossmember can be installed. The passenger- and driver-side lower control arm mounts are also trimmed to create clearance for the differential/axle assembly.
After the install, we had the opportunity to watch the truck in action off-highway in the Louisiana backcountry. From outside the vehicle, the truck's suspension was as quiet as stock as it absorbed the rough terrain and the improvements in ground clearance clearly made for a less stressful wheeling experience for the driver as the trucks body and frame were now further from the ground. It's also worth noting that since the owner chose to increase tire diameter by only two inches, he probably won't have to re-gear the truck.
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