We see a lot of great modern engine setups in classic cars and trucks, but one we don’t see a lot of is a diesel swap. The diesel engine has plenty of horsepower and torque, while still achieving better fuel economy than their gasoline-fueled counterparts, but we just don’t see as many of them as we’d like to. That’s why we jumped on it when Walt Carmen of Gilboa, New York, reached out and told us about his awesome, twin-turbo Duramax diesel-powered 1957 Chevrolet wagon.
The project didn’t start with the intentions of a show-worthy build, but as things started to go together with the diesel swap, Walt had a change of heart. “I was going to make a rat rod out of it, but after seeing how well things fit, I had to do it right,” Walt explained. “So, I took it all apart and sand blasted the body inside and out.”
The original plan would have made a differently styled rat rod instead of the show worthy build it turned out to be. As you can imagine, the idea of putting together the diesel-powered ’57 would be a lot simpler if you weren’t constraining yourself to a restoration instead of a, what you see is what you get, rat rod.
The project shifted directions, when Walt was putting it together and found that things were just fitting together too well, and that it would be better to finish it right. He started with a 2006 GMC Savana van, and that’s where the running gear and most of the electrical components came from. “The LBX Duramax engine, 4L85-E transmission, radiator, intercooler, brake system, steering column, and complete wiring harness all came from this van,” Walt listed.
He took the wagon off the frame, and used a frame from a 1996 Caprice for extra structural support. At this point, he thought it was still going to end up as a rat rod, but once he set the Duramax on the frame and the body over top of that, it all fit together much better than expected. “It turned out to sit right in there like it was meant to,” he explained. “No cutting the firewall or transmission tunnel using the 4L85-E transmission.” Once things were setup and he saw that it was working better than he had even envisioned, he decided he was going to do it right.
In building this car, Walt used almost all of the electrical system from the van. More than that, he molded the instrument cluster to the dash in the ’57. He even used the steering column, ran all the wiring from the van’s wiper system, and used the brake booster—none of which required any significant modification. The steering column fit through the stock hole, and even the brake booster fit through the factory firewall hole.
From there, he had the car painted, and at first glance, thought his combo was a failure and almost rolled it right back in for a repaint. “After putting on some of the stainless,” Walt said, “She was born. It looked great” At that point, they came up with the name Dirty Maxine, since trucks with this kind of swap often go by the name Dirty Max.
Along with the significant engine and transmission changeover, Walt knew he was going to need a much stronger rearend, so he went with a Moser M9 with a Wavetrac positraction, 2.91 gearing, and 35-spline axles. The complete drivetrain is an impressive setup for a 1957 Chevy wagon, and one that you’d likely never expect. If it weren’t for the overt color combination on this car, there is no way you’d expect such an aggressive powerplant. The change would be obvious, however, once he starts it and you feel that rumble deep down in your chest from the diesel powerplant.
The car has also been treated to a custom interior that matches nicely with its exterior color scheme. The suspension has been upgraded with RideTech air ride, and new upper and lower control arms. The engine has been reprogrammed by Rob Codden at ATP to improve output from 250 horsepower, to a generous 500 horsepower.
Walt has been running the 4L85-E transmission for two years with no trouble. But, since he added the twin-turbo setup earlier this year, it has been feeling the strain of that additional power. Now, with a new tune from Rob, he is getting about 620 horsepower, and it doesn’t end there.
Walt will be installing a new Rossler transmission with billet drag-race parts that will be ready to handle up to 1,500 horsepower. At the same time, he is planning on using larger injectors to push the horsepower up to around 750 to 800, and the torque to around 1,300 lb./ft! “Unbelievably, I’m getting around 30 mpg on the highway if I can keep my foot out of it,” Walt explained. “If not, 15 mpg running it hard!”