When John Marston graduated high school, he wanted one thing-a red, diesel-powered Chevrolet Silverado. He got his wish in the form of a brand-new, '07 extended-cab model, which he traded a gas version for at Sebago Lake Chevrolet in Windham, Maine. A couple of years later, he got something just as special-albeit somewhat unexpected-his son John III.

While dad admits the arrival of his son briefly slowed down his plans to customize his ride, he's made slow, steady progress on building an eight-lug truck that definitely stands out.

Like many performance enthusiasts in his age group, Marston, now 21, went with a diesel because, "there's a lot more you can do to it," when compared to a gas powerplant.

While many owners do their own upgrades, Marston went to the professionals at New England Off Road Outfitters in Portland, Maine. Greg Legnard, co-owner of the performance accessories company, said his business does many more upgrades on diesels than on gas motors.

On the performance side, Marston upgraded the 6.6L Duramax diesel with a Banks intercooler and air cleaner that, combined, increased power by 100 ponies. A Bully Dog Outlook four-stage tuner boosts output by 126 hp and 213 lb-ft of torque when in the Extreme setting, which is the only position Marston runs in. What else would you expect from a 21-year-old? The Bully Dog's four settings are Stock, Towing, Performance, and Extreme. Martson also said he gets about 16 mpg when making those late-night runs to the store for formula or diapers.

What makes the Bully Dog so popular is its user friendliness. You simply toggle through the four driving positions on the fly. The small screen is easy to use and looks cleaner than three individual gauges that would be mounted on the door pillar in old-school installations.

To help the engine breathe more easily, Marston initially went with a Banks Monster exhaust system installed behind the catalytic converter. He soon replaced that with twin stacks behind the cab and removed the converter and muffler. Fortunately for him, the state of Maine does not perform emissions testing during its annual inspections.

Of course, if you're going to boost a truck's performance, you've got to make it look good to get noticed. A Pro Comp 6-inch lift with single shocks up front is a great way to get people to look at a truck. So are the General Grabber 35-inch tires on Moto Metal 16-inch (10 inches wide) rims. He had 12-inch-wide rims, but Maine state laws restrict legal rim size to 2 inches above stock, so he went back to the 10-inch models. The chrome and black pattern works well with the truck's deep, fire-engine red paint to make Marston's ride a real head-turner. The Marston Tree Service decals were done by Sebago Sign Works in Raymond, Maine. Take a close look at the hood and you'll see the custom silver 6.6L Duramax diesel decals (which are also on the driver- and passenger-side doors) in the same metalflake as the his-and-her signage for John and his girlfriend, Natalie Angers.

While some 21-year-olds have no appreciation for what they're driving, Marston knows better than most what's under the hood, having spent three years in a vocational technical program focused on engine building and auto technician instruction at Oxford High School in Oxford, Maine. For now, he's in the family business, which owns a tree service, a landscaping division that Marston works for, and three bottle-and-can redemption centers/convenience stores in southwestern Maine.

All told, Marston estimated that he spent between $1,500 and $2,000 on the first round of upgrades. He was all set to start on round two when John III arrived. Dad said that Junior already likes to sit in his lap and try to shift and steer the truck, so the little one's appreciation for custom work is already in place.

But Marston's goals for the truck haven't changed. He wants to go to bigger injectors such as the Dynomites. Then he wants to download the Crazy Larry upgrade for the engine's ECM, which is a likely move since the program is free. A two-stage turbocharger is in the future plans and then Marston will upgrade the transmission, which New England Off Road's Legnard strongly recommends. He'd like to add some airbags to the suspension to cushion the ride, and to make it easier to get his son in the truck, Marston will bolt on some step bars. He said he plans to keep the truck-which has 20,000 miles on it-forever. "I'll give it to my boy someday," he said. And no doubt, the son will appreciate it as much as his father.