How Roadster Shop built the baddest 1990 Slammed OBS Chevy Truck in the Land!

The craftsmen at the Roadster Shop never know what offbeat project might turn up at their shop for a high-end makeover. Such was the case with past customer Jon Hall and his 1990 Chevrolet OBS truck build. Hall owns Shadow Rods where he repops flathead V-8 engines out of aluminum that are stronger and more powerful than the original mills. He’s had a ton of higher-end builds done at top shops, including Roadster Shop, and has built his own share of hot rods. As Roadster Shop’s Jeremy Gerber told HOT ROD, “He is a wildly talented guy that can not only dream up some crazy stuff, but he has the skills and resources to make it, as well. He has built some of the most elaborate stamping dies I have ever seen to stamp hot rod parts. He also has more experience with welding thin-gauge metals than probably anyone I know and can create things that would humble just about any pro hot rod builder out there.”

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So what’s the catch? Hall has been on this earth for around 80 years, so it was a bit shocking when he told the Roadster Shop he’d seen their new OBS Low Pro Chassis and wanted them to use it for a rebuild of his own retro 1990 OBS Chevy truck.

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As Gerber explained, “The truck arrived, and it is an absolute gem of a ’90s street truck survivor! Jon bought it new in 1990 and drove it straight home from the dealership and started modifying it. The shaved handles, modified stepside bed, roll pan, sport mirrors, custom front bumper/spoiler, and all the other trick ’90s OG accessories were his handiwork from 1990. It sat on a set of OG 15-inch Boyds five-spoke wheels with BFG Comp TA tires. It was basically the exact truck someone would try extremely hard to duplicate today as a throwback. So it was a killer start for us.”

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Just like any other hot rod build, the OBS was full of challenges. But many of these were eliminated through the massive amount of engineering and R&D that went into designing the new RS Low Pro Chassis.

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“The single biggest challenge is getting these trucks to drive and function at the ride height you want to see them at,” Gerber said. “For being such wide vehicles, they are quite deceiving when it comes to track width. We faced some major challenges during the chassis design to get the track width narrowed up to where we could accommodate a 29-inch-tall tire with a 10-inch section width and achieve a proper steering angle. I have seen a lot of glamour shots of slammed OBS trucks cruising down the highway. I have come to find out that those must have been west Texas highways that are dead straight for hundreds of miles, because you cannot turn many of those trucks more than a few degrees. We wanted to build something that worked as good as it looked. We can sit the truck at a very low ride height and comfortable cruise it while retaining full drivability and functionality.”

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Gerber went on to explain, “The other huge hurdle was to design a chassis that nearly lays the frame when aired out with a 30-inch-tall rear tire but requires zero modifications to the height of the bed floor. We really wanted to retain the full functionality of the pickup bed and not give it up to a large step or raised bed floor. I was adamant that we accomplish this, no matter what it took. I think it largely stemmed from the fact that I grew up with these trucks, I drove a 95 Z-71 in high school and shortly after. To me it was a daily-driven truck, and it had to be functional to haul dirt bikes, toys, and whatever crap I needed to throw in the back. I always looked at the C-10s and ’50s trucks as being ‘old classics’ that you can get away with giving up a bit of the bed functionality.”

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The exterior was left as is since it showed up with all the cool mods that had already been done to it. To accommodate the new chassis, RS used their CAD-designed sheetmetal package that’s available to anyone who wants to tackle an OBS project like this themselves.

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The wheels were designed and machined by Chris Sage at Sage Speed and Custom to copy the look of 1990s ZR1 C4 ’Vette wheels. It took a lot of work to get the proportions of the 20-inch wheels right and keep the OG sawblade OEM look. The backspacing was also a challenge to nail down, but the wheels just look right on the slammed OBS truck.

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Dressing up the engine to look right was a real head-scratcher. RS really wanted to design an over-the-top TPI throwback intake manifold for the LS3 engine grafted under the hood but came up with a more budget-friendly idea. Their TPI-styled trim plate works with an off-the-shelf Holley intake manifold and does a great job of selling the TPI idea without breaking the bank.

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For the interior, RS kept the vintage retro vibe but updated the guts with Dakota Digital HDX gauges, Vintage Air Gen V A/C, a kickass audio system, and tons of custom upholstery done in-house.

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The result is an OBS truck that keeps its 1990s retro feel but with a huge dose of 2025 functionality. It can drive, turn, and be driven without all the compromises that had to be endured back in the day with a slammed OBS build of that era. Be sure to check out the massive build image gallery to see how Roadster Shop reimagined this 1990 stepside Chevy OBS truck!

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Work Performed

Chassis

• RS Low Pro air bagged bolt on OBS chassis. This is our production Low Pro chassis that incorporates a low-profile trailing arm style IRS rear suspension that allows the truck to nearly lay the frame when aired out without the need for any alterations to the height of the bed floor.
• 15-inch Baer six-piston brakes with color matched logos
• Ridetech single adjustable shocks
• AccuAir E-Level air management
• Front and rear DOM sway bars

Mechanicals

• GM LS3 430-hp crate engine
• Holley intake modified to accept RS custom-designed and machined TPI cover
• Billet specialties valve covers machined with “Roadster Shop/Shadow Rods” abbreviation logo
• Holley Serpentine drive
• Monochromatic Cerakote on all engine components
• GM e98 ECU with PSI Harness
• Bowler 4l60E Tur-Street series transmission
• Stainless custom tank with GM Camaro pump and VaporWorx returnless PWM fuel controller
• 2.5-inch stainless exhaust RS fabricated with Vibrant resonators and Borla mufflers
• Rad Ride by Troy Tesla power booster assembly
• PWR aluminum crossflow radiator bolt in assembly for RS OBS Low Pro with 19-inch PWM fan
• American Autowire HWY 22 harness

Metalwork

• Exterior all left as is with original modifications untouched
• RS CAD-designed sheetmetal package was laser cut, fabbed, and installed. All of these parts are available for customers installing a RS Low Pro Chassis to speed up the process and consist of the following:
• Front inner wheelhouses
• Outer fender structure notch kit to allow adequate steering angle
• Toe board clearance panels to allow large-diameter tires to turn full lock at any ride height
• Smooth firewall panel
• Rear wheel tubs (available for both stepside and fleetside)
• Modified rear roll pan to incorporate era-appropriate rectangle stainless exhaust tips
• Utilized factory gas door to fabricate a battery tender plug-in
• Custom fabricated core support close out panel and wiper motor cover

Interior

• Factory OBS low-back buckets and center console
• Complete interior reupholstered in-house at RS
• Dakota digital HDX cluster
• Factory column and wheel
• Vintage air Gen V A/C
• Kicker KMC5 marine head unit
• Faux equalizer designed and machined by RS for center of dash
• Interior was kept very simple and original feeling to retain the OG look and feel of the truck

Wheels and tires

• Front Tires: Bridgestone Dueler H/P Sport 255/45R20 Sidewalls shaved by Diamondback Tire
• Rear Tires: Bridgestone Dueler H/P Sport 305/40ZR20
• Wheels designed and machined by Chris Sage at Sage Speed & Custom to mimic the ’90s ZRI C4 Corvette wheel in a brushed finish. They were clear Cerakoted by RS
• Lots of thought was put into carefully nailing the proportions of each part of the wheel to properly achieve the OG sawblade OEM look
• Wheel backspaces were manipulated to get the exact outer lip profile that was most desirable. An integrated rear spacer was used to reduce the outer dish. The wheel backspace specs cannot be provided as they would be difficult to repeat.