When Chevrolet designed what would become known as the “Old Body Style” (OBS) generation of Chevy trucks (1988-1998), they focused on making a pickup that was capable of hauling heavy loads for days on end. Today, companies such as Speedtech Performance are engineering components for these trucks so they can haul in a very different way. This new ExtReme OBS chassis featuring independent rear suspension (IRS) is engineered to take your Chevy truck’s handling to the extreme.
The foundation for the OBS chassis is Speedtech’s box-welded frame that utilizes tab-through-frame gussets for the ultimate in torsional rigidity. The suspension features custom-designed upper and lower control arms with ample clearance to accommodate wide wheels. A Sweet Manufacturing dual power rack and pinion makes turning a breeze and splined sway bars, along with a variety of spring rate offerings, tailor the ride of your ride while keeping your bumpers level with the horizon.
There are also Speedtech’s exclusive forged spindles up front which are machined to use C7 Corvette hubs and a maintenance-free, sealed bearing assembly. The spindles are forged from high-quality, lightweight 7075 aerospace aluminum and feature an optimized geometry of Speedtech’s design. The result is a chassis that provides an increased Ackerman angle, and improved scrub radius, and requires less caster to achieve an optimum tire contact patch. There is also virtually zero bump steer throughout the full travel of the suspension. The spindles are designed to utilize the popular C5 and C6 Corvette caliper mounting which allows for a vast array of brake options.
In addition to this fast-handling OBS chassis, Speedtech is now offering independent rear suspension options including low-mount, or high-mounted, cantilevered shock options. The benefits of a cantilevered shock mounting include a significantly increased rear shock motion ratio (110 percent), which allows for better rear grip with a lower spring rate.
The OBS chassis is also tunable via three-piece tubular sway bars that feature three mounting points to allow adjustability without removing the bars. Roll center is adjustable in the rear based on the lower control arm mounting position and front and rear ride height is also adjustable through the supplied coilover shocks.
The chassis features fully-adjustable crossmembers that will accommodate all engine and transmission combinations. All Speedtech OBS chassis IRS packages come standard with an E-brake and feature JRI single-adjustable coilover shocks that have been custom valved for the Speedtech chassis. Each JRI shock is fitted with your choice of spring rate, depending on the application.
Speedtech also offers a variety of options to help you complete your project, such as stainless steel headers for most engines, urethane engine and transmission mounts, an aluminum rearend center section with your choice of gear ratio, and quality brake packages from BAER or Wilwood. A Rick’s stainless steel fuel tank is available as an option, as well as an aluminum, cross-flow radiator with twin SPAL fans, shroud, billet overflow tank, billet radiator cap, and all wiring and relays that are custom built to fit the OBS chassis. Customers interested in a Speedtech ExtReme chassis are recommended to call and speak with one of Speedtech’s sales representatives to ensure they receive the perfect chassis for their OBS Chevy truck.