A Slammed 1951 GMC 3800 With Detroit Diesel Power

Where Utility Meets Style

A service truck doesn’t always have to be built to meet stringent work site guidelines. It can be as sleek, stylish, and exciting as any custom showpiece. In fact, introducing a sense of playfulness into the workplace has been good for business according to Doug Smith, owner of C.L. Smith Trucking, Inc. in Woodland, California. He had a vision of creating a more “hipper” version of the Peterbilt semis in his fleet, and the 1951 GMC 3800 he chose to work with proved to be the perfect vehicle to mold into shape.

The 3800 is the heavy-duty version of GM’s famous 3100 Advance Design pickup, so it would seamlessly integrate into Doug’s existing fleet of work trucks. To kickstart the project of transforming the classic utilitarian Chevy into something much more sophisticated, Doug reached out to Marshall Customs in Sacramento, California, to tailor a reimagined chassis system that promotes a much lower, aggressive stance.

Starting by fabricating a one-off frame, Marshall Customs then utilized an F-550 rear axle and assorted C30 parts to piece it together. Next, a foursome of Air Lift Dominator air bags, along with the necessary compressor and air management components, were added to allow the 3800 to be aired up or down depending on Doug’s mood. To complete the fully adjustable suspension setup, Doug selected a set of 22-inch American Force wheels complete with spiked lug nut covers that mimic the big rig aesthetic he’s used to.

Next, the time came to swap out the GMC’s worn engine, and what better replacement is there than a Detroit Diesel 212 ci 4-53TI power plant? Built by J&H Marine, the DD engine was soon treated to a turbocharger, a bypass blower, and a charge intercooler, along with upsized N-65 injectors with the timing set at 1.460. A 1997-’01 Dodge NU4500 transmission was then chosen to back the freshly planted diesel mill. While all those modifications were a huge improvement over the GMC’s previous drivetrain, Marshall Customs had to go a step further with the truck’s exhaust system. Further embracing the big rig vibe, dual exhaust stacks were crafted to give the GMC true coal-blowing abilities. Doug was closer to taking his 3800 out for a spin, but there was still more important work left to be done.

The following phase of the project was to update the 3800’s outward appearance—first with the inclusion of a utility box bed that is as functional as it is cool to see on the back of a slammed classic truck’s cab. Marshall Customs then fabricated a custom grille and hood before wiring up HID headlights. The truck was soon turned over to Alfredo Bravo so he could apply a fresh coat of paint. SorD Boardshop in Woodland, California, was then asked to apply the finishing details to the GMC’s exterior. The selected yellow hue is a familiar color that adorns the rest of Doug’s Peterbilt fleet, which allows the truck to blend right in with the rest of the crew.

Only the interior was left to rehab, and to pull off a simple yet effective overhaul, Doug trusted Premier Upholstery in Sacramento, California, to handle the job. A new bench seat from Wise Guys was ordered and covered in black vinyl material, as were the door panel inserts for a cohesive touch of class. An Accuair e-Level+ control unit allows Doug to cycle through pre-set ride height settings, and a custom shifter gives him a unique grasp on controlling his rig.

While the entire build process only took a year to complete, Doug can attest to running into his fair share of problematic roadblocks; however, there was always a solution to clear the obstacles. The engine work was the trickiest part of the process, and after the first bout of modifications didn’t work out, a second round was necessary to work out all the kinks.

Once the dust settled, Doug had time to reflect on the positive experience of working with Marshall Customs during the project. Since completion, the 3800 has been taken to show off at Autorama and C10 Intervention, and the response from the crowd has been nothing but praise and positivity. Doug has combined his respect for his trade and his love of custom rides to create the ideal blend of both worlds, where utility meets style.

Photos by Brett Macadam