Slammed in Japan, $60,000 Frames in Illinois: The OBS Chevy Has Become the Street Truck Scene's Main Platform

Somewhere in Oshu, a small city in Iwate Prefecture in northern Japan, a black 1997 Chevrolet C3500 dually rollback sits on air suspension with its frame almost on the pavement. The Drive found it in October through an Instagram account that spots odd cars, listed at a dealer called Passion Co. for 7.8 million yen, about $52,000 at the time. It has a 454 big-block, a column-shifted automatic, shaved bumpers, a billet grille and chrome five-spoke wheels. It is a work truck that was built to haul broken cars, and someone in Japan turned it into a show truck.

Ten days later, The Drive reported on something that sounds like the opposite end of the scene. Roadster Shop, the Illinois chassis builder, had released a brand-new frame for the same family of trucks, starting at $45,000 and climbing to about $60,000 with options. The Drive's headline pointed out that the trucks it fits often sell for around $15,000.

Put those two stories side by side and they say the same thing. The 1988 to 1998 GM full-size pickup, the truck everybody calls OBS, has finished its long trip from cheap beater to a platform that supports its own industry.

What OBS means, and why now

OBS stands for old body style, the nickname for GM's GMT400 trucks built from 1988 through 1998. Roadster Shop's Pat Webster told Street Muscle at SEMA in 2021 that OBS-style trucks were "super hot right now, but they have their limitations." Five years later the heat has not cooled. If anything, the products have gotten more serious.

The reasons are not mysterious. These trucks are simple, plentiful and squarely in the age range where people who grew up riding in them now have money to build one. They have the clean, flat-sided shape that The Drive's Stephen Edelstein called some of the best-looking trucks GM has ever produced. And they come from the era just before trucks got huge, so a regular cab short bed still looks right slammed to the ground.

The slammed side

Lowered OBS trucks are the foundation of the modern street truck look, and Roadster Shop built a chassis for exactly that crowd years ago. At SEMA 2021, Webster explained to Street Muscle what customers were asking for. "The big thing that we are seeing through the industry with OBS trucks is guys want that lowered stance, they want that to slam it, but they also want the big ass tires in the back," he said.

That Low Pro chassis was designed to fit a 405 series rear tire with tubs, without raising the bed floor the way many other chassis did. Webster's explanation of why that mattered was pure truck guy logic: raise the bed floor, he said, and a coffee cup in the back goes flying, and "it's no longer a bed." The chassis used an independent rear with C7 Corvette spindle and hub assemblies and Baer brakes, with pockets built into the frame to route air lines from front to back for bagged builds.

It also bolted engines in a way the LS crowd appreciated. Webster said the front engine mounts and crossmember were completely bolt-on, so a customer could spec an LS with a T56 and later swap to a newer GM engine without refabricating anything.

The other direction

The new RS4 OBS chassis The Drive covered in October is not a slammed-truck frame. It is a heavy-duty, four-link, solid-axle chassis with a Currie Dana 44 up front and a Dana 60 in the rear, Fox 2.5 coilovers that Roadster Shop valves in-house and an optional Atlas transfer case for four-wheel drive. On its website, Roadster Shop says the geometry is designed to "optimize anti-dive, anti-squat, and suspension articulation," and the links use what it calls "massive sealed x-axis flex joints," which The Drive noted should help with noise, vibration and durability compared to spherical joints.

Engine choices cover the whole range. It accepts the original 350 TBI V8 or something much angrier, with mount kits for other small-block and big-block Chevys, LS engines and LT1 or LT4 engines. Caleb Jacobs of The Drive, who said he has worked on plenty of GMT400 trucks, wrote that he was "fully confident this is unlike any GMT400 componentry I've personally worked with."

That is the interesting part. When a chassis company builds a $45,000 frame for a truck, it is betting there are enough owners willing to spend three or four times the truck's value underneath it. A few years ago the OBS was the budget alternative to a square body. Now it gets the same treatment as the most expensive classic truck builds.

Japan gets it

The Passion Co. rollback is the other tell. A left-hand-drive C3500 with a big-block, air ride and a flatbed is the kind of oddball that gets noticed anywhere, and this one was built and sold in rural Japan. Edelstein described it as "slammed on air suspension, with clean-looking chrome five-spoke wheels that complement a very clean exterior." The interior is a two-tone tan cabin with a Chevy bowtie mat on the floor.

At roughly $52,000 before shipping, it is not cheap. But it shows how far the shape has traveled. A truck that was a commercial tool in 1997 is now a show piece on the other side of the Pacific, built in the same lowered style American street truck builders love.

What comes after OBS

The surest sign a platform has peaked is when the aftermarket starts looking at what comes next. In October, LSX Magazine ran down QA1's bolt-on suspension packages for 1999 to 2006 Silverados and Sierras, the trucks the scene calls NBS, for new body style, and which the magazine described as the OBS successor.

The kits run from a Level 1 Lowering Kit with up to five inches of front drop and six inches in the rear, all bolt-in with no cutting or welding, up to a Level 2 package that replaces the factory leaf springs with a multi-link torque-arm rear and a Panhard bar. LSX Magazine pitched it at everything from clean street cruisers to boosted LS-powered trucks. The NBS came from the factory with Gen III LS-family V8s, which makes it a natural next step for the same people who have been swapping LS engines into OBS trucks.

The bottom line

The OBS is following the square body's path. First it was cheap and everywhere. Then the people who grew up with it started building them. Then the aftermarket caught up with complete chassis, suspension packages and parts catalogs. Now the trucks are being slammed in Japan and fitted with frames that cost more than a lot of new trucks.

For builders who bought an OBS for a few grand five years ago, that is good news. For anyone still hoping to find one cheap, it is a warning. And for the NBS owners watching QA1 roll out kits for their trucks, it might be a preview.