
Tech
IMAGES BY LISA JONESor many of us, hearing a truck described as “old” conjures up visions of a rusty hulk sitting in a farmer’s field. But today “old” is now included in the term “old body style” (OBS), which is commonly used to identify General Motors trucks produced between 1988 and 1998. The rise in popularity of these pickups is easy to understand as they are new enough that examples in good condition are readily available, they’re affordable, and look great with easily made modifications. All things considered, OBS Chevy and GMC trucks may well be the best bang for your buck on today’s classic truck performance scene.
One of the most common modifications to OBS trucks is lowering the ride height all around. But while dropping these pickups helps visually, handling and ride quality often suffer as a result of lowering done incorrectly. Suspension travel is often reduced, resulting in a rough ride, and changes in steering geometry can lead to vague handling and accelerated tire wear. More than 20 years ago Art Morrison of Art Morrison Enterprises (AME) saw the need for a bolt-on replacement chassis that offered that desirable contemporary stance with sports car–like handling along with full suspension travel for a comfortable ride. Today, under the leadership of company president, Matt Jones, that legacy continues with AME’s expanded line of replacement chassis, which now includes the GT Sport Series for OBS Chevrolet and GMC pickups.
Like GT Sport chassis, the OBS version is engineered for that specific series of trucks. The mandrel-formed frame is assembled and welded in a dedicated fixture. Up front is AME’s Sport IFS modern geometry that offers exceptional straight-line stability coupled with high-speed cornering ability. Tubular control arms are used with Wilwood spindles that will accept a range of disc brake components with rotors from 12 to 15 inches and calipers, including Dynalite, Dynapro, Superlite, and Aero6. A custom-valved 17.5:1 power rack-and-pinion steering is included and a variety of coilover shocks are available.
In the rear, the chassis uses hefty 1.375-inch-diameter four-links with Johnny Joints on both ends for maximum suspension articulation. A Watts link is used to keep the axle housing centered under the frame. As for engine mounts, the mounts to accept virtually any Chevrolet/GM V-8 engine are available and all popular manual and automatic transmissions can be accommodated.
With the new OBS chassis designed and in production Jones decided to build a truck to show how easily it could be done. The chassis installation is basically a remove-and-replace operation. The only fabrication required is the removal of a support under the bed. Expensive custom headers aren’t required, as anything that fits the stock chassis will work and exhaust can be routed in a traditional manner (instead of down one side of the chassis). The stock A/C system can be retained, and although there are some underhood components that may have to be relocated, there are accessory brackets available to make that easy to do. While they aren’t required, modified inner fender panels will allow the lowest ride height possible with maximum suspension travel.
Despite these trucks being called the old body style, they are still new enough that examples can be found in quite good shape. These are solid, well-built trucks that currently don’t demand the high prices that others bring, but then you get what you pay for. Jones was looking for one that had no rust and didn’t need to be repainted and that’s just what he found. While it’s true a pristine truck like this one will normally carry a premium price tag, by not having to budget for paint- and bodywork the project will be more affordable in the long run.
Building an OBS GM pickup can be a more affordable and a less complicated process than many other trucks. Certainly the AME chassis swap couldn’t be easier and the results couldn’t be better, but we’re not done with it yet. We’ll bring you more of what’s new for OBS pickups soon.
artmorrison.com