Roadster Shop 1976 K10 GM Restomod Truck: 2023 SEMA Show

We love our classic trucks, and GM’s square body trucks have gained popularity and become harder to find. These trucks have a nice look, but compared to modern trucks, they don’t have the same road manners and performance. But what if you could have the classic, square-bodied style of the truck with all the character and drivability of a modern GM truck?

The Gerber brothers at Roadster Shop noticed that they were receiving more and more orders for truck bodies and decided to create a line to serve this growing market. This series evolved into the Legendary Series of GM trucks, covering 1973 to 1980 models.

Thousands of hours and years of research and development conducted by Mike O’Brien, the Roadster Shop’s lead engineer, made this program possible. This extreme effort resulted in a truck of flawless performance with modern day-to-day drivability, all wrapped in a classic truck body. More than 20,000 test miles were put into the RS Legend concept truck before production began. This ensures that the trucks have better than OEM ride quality, crisp handling, and quick acceleration, all in a package that can be driven daily if you so desire.

They offer three versions of the Legend series. The first is where they ship you the complete chassis and driveline (including wiring) as a do-it-yourself kit for your existing truck. The second option, called Survivor Series, is where you send them your truck and they transfer the body to the chassis and hand you a modern K10 truck similar to the one you started with. The last option is similar to ordering a truck from a dealership. You tell them the color, if you want an LT1 engine or a supercharged LT4 engine, then you choose the interior options, and they build it just for you. We decided to follow a 1976 K10 truck (serial number 004) that RS was building for the 2023 SEMA show to see what it takes to inject modern performance into a classic GM truck.

An old truck needs a vintage body. The good news is that the K10’s chassis is shared with the standard C10, so not only are there plenty of bodies out there, but there’s also plenty of aftermarket support in terms of body panels and other parts.

For their ’76 K10 SEMA build, they chose a blue and white Catalina paint scheme that also ties in with their company colors. This is truck number 004, and has earned the nickname “Urban Cowboy.”

The bodywork for the cab and truck bed is the same as any other custom vehicle built at the Roadster Shop, and includes panel preparation, correcting gaps, and getting everything done right.

We asked Phil Gerber and he said they’ll paint the truck any color you want, but we personally like the idea of ​​the retro-looking colors and two-tone layouts.

To simplify the construction of many of these trucks, everything is planned using computer-aided design (CAD). The Roadster Shop chassis takes most of the parts from a modern GM truck, including the driveline, fuel system (including tank), brakes, differential, transfer case, and even all the emissions equipment.

Here you can see the RS chassis loaded with all GM truck parts. The end result is a vintage truck that rides and drives better than the modern truck on the lot.

For the SEMA 1976 K10, the team opted for the 460-hp LT1 engine, but for a few extra dollars, you could get a 650-hp LT4. Backing up for the LT is an 8L90 eight-speed automatic transmission.

With the OE GM Performance body filled, the painted cab is then bolted into place. The frame was designed by RS to accept all modern GM components as well as OEM electric rack-and-pinion steering.

RS wanted the interior to have a vintage look, but with modern materials and construction standards. To get there, the boards were designed entirely using CAD and then 3D printed (provided in-house by Chris Gray).

There are color options, but we like the Saddle Tan with water-dipped shingles from Liquid Concepts. Other interior features include a 15-inch square-spoke steering wheel wrapped in RS Legend suede and a billet trim to integrate the Kicker head unit into the factory dashboard frame. Custom exterior door handles use modern GM latches.

The modern drivetrain and added technology means there is a lot more wiring than on the K10 truck. Even features like a HD transfer case with an “on-the-fly” four-wheel drive button are present.

If you didn’t know better, you might think you’re looking under a new GM truck. The factory exhaust manifolds are connected to a Y-pipe system complete with OEM catalytic converters paired with a 3.5-inch stainless exhaust with Borla SS mufflers and dual 2.5-inch stainless tailpipes. GM OEM IFS suspension components use Fox RS valved coils up front and Deavers multi-leaf rear leaf springs along with custom RS valved Fox shocks and a GM 12 bolt in the rear. There is also a modern factory GM fuel system with a GM plastic tank, integral hitch kit, and factory spare tire. The K10 is designed to be used as a truck, so there is an auxiliary bag system on board with a wireless remote control.

At this point you may think you are just checking out a nicely restored 1976 K10 truck. There are no stock steel wheels here, though – Billet Specialties’ 17×9-inch Legend Series wheels are designed to have an original equipment look and accept square hubcaps! The wheels are wrapped in Toyo AT/III 305/70R17 rubber.

The goal was to use as many factory GM components as possible, including items like the brake booster and master switch. RS also wanted to use factory-proven cooling components, so CAD designed a complete core support to attach it to the old K10 chassis. You can check out this basic support better in the gallery.

After all the trim was installed and the K10 was finished, it was sent to the Roadster Shop’s in-house tuning facility to order everything. Next, the updated 1976 K10 was loaded and shipped to the 2023 SEMA Show, where you can find it located in front of the main concourse in Space V045.

Photos courtesy of Roadster Shop