Take a look at this big, high-end southern New England beast! It’s a 2017 dually GMC Sierra Denali 3500HD with the L5P Duramax engine and it has undergone a ton of work! Owned by John McKim of East Lyme, Conn., this truck will blow away anyone who gets to see it and it has become a dream come true for the owner.

Truck Life

“I always loved a nice thick dually,” says John. “This build was actually an idea that started seven years ago when I was in college at the University of Northwestern Ohio. I liked that I could still use a dually for travel, work or anything I wanted to and I was sold.”

John had owned two different 24-valve Cummins over a three-year period and then switched over to Duramax about three to four years ago with a 2005 LLY, and that’s when he fell in love with the Duramax platform.

“I knew the truck I wanted to build was a Duramax and when the L5P came out, I wanted one so bad,” recalls John. “They looked great, performed well and had the potential to sound amazing as well. Then I started to work on my vision once I got my hands on this truck.”

This truck is John’s pleasure vehicle in addition to his daily driver, as he has quite a bit of fun with it.

“The main reason I went with a dually was because I tow my Hellcat Dodge Charger a lot,” he says. “I’ll also be towing it to all different drag strips next year, once it gets done. I’ll also be looking to buy a fifth-wheel camper so I could travel all over the country with it.”

So far, John hasn’t traveled much with the truck, but he has driven out to Ohio for some upgrades and back and forth to New Jersey several times to the shop that’s building his Charger. After buying the truck bone-stock at a dealership in Pennsylvania in May of 2020, it wasn’t long before he really went to town with the daily driver. He looks forward to traveling with the rig more in the future.

Upgrades

The first area John dug into with his build was the engine, and he began the work there by adding a Banks cold air intake and an Edge Pulsar tuner. Of course that wasn’t enough, though, as one upgrade simply led to another for him. Next, he leveled off the truck and added FOX Performance Series 2.0 dual reservoir shocks on each wheel, along with a steering stabilizer kit and Kryptonite Death Grip tie rods. With that, the truck needed some new shoes, so John added 22-inch Fuel wheels wrapped in 33-inch Toyo Open Country M/T tires. With the bold leveling and wheel setup completed, he figured it would come off even stronger with a lighting setup, so he went to that next.

“I talked to some great people over at Apex Off-Road Lighting and got a 16-piece RGBW (Red, Green, Blue & White) rock light kit,” he says. “Then I placed two in each wheel well, two in the grille and then the rest scattered around under the truck.”

This helped John develop an addiction to lights; within no time, the black GMC became a lighting machine as he then added Spyder fiber optic taillights, a Recon third brake light, Recon side marker lights, Spec-D Tuning headlights with a Diode Dynamics high-intensity discharge (HID) conversion kit, a Vivid Light Bars RGBW flow GMC emblem, as well as switch-back LED door handle lights, switch-back LED cab lights and switch-back sequential LED mirror lights from Midsouth LED.

A Step Up

The lighting setup gives a truck a ton of character, especially at night or anywhere in the dark. He also replaced the factory steps with AMP Research PowerSteps, as he felt the chrome of the steps was too much to handle. The steps might be somewhat overkill for a truck that doesn’t really have a big lift, but they still are helpful, especially for shorter people who may want to ride in the truck. Additionally, John had train horns installed along with a sound system consisting of two Alpine Type R 10-inch speakers. With all of this, the truck is now quite a party vehicle! Much of these accessories were installed by John’s friend J.D. at Northeast Truck & Off-Road in Groton, Conn., whom he has a great relationship with. John did some of the work himself as well, though.

Topping off the aesthetics, John had the truck fully paint-matched and ceramic-coated by Stephen White at Elite Auto Detailing in South Windsor, Conn.

Fun Changes

Next came what John calls the “fun changes.” The Edge Pulsar was then removed and replaced with an HP Tuners ECM and TCM with CTT tunes. A Wehrli Custom Fabrication high-flow kit with hot and cold side intercooler pipes and a turbo inlet horn were also added. Finishing everything off for the engine side is a 3.5-inch exhaust down pipe with a 5-inch tip at the end. For this work, John took the truck to GI Service Center in Spencerville, Ohio.

“I send the truck to this shop for everything mechanical,” John laughs. “It’s a lot of distance, but if that doesn’t say I trust them, I don’t know what does.”

Conclusion

Looking back on everything he’s done thus far, John feels it couldn’t have turned out any better and he loves his show-worthy truck. That being said, it really is a shame that COVID-19 shut everything in truck shows down for almost a full year now. However, John has still been able to occasionally take the truck out to Connecticut’s Berlin Turnpike for local car and truck meets on Friday and Saturday nights. He does plan to attend larger events in the future when they’re able to happen again.

Also in the future, he plans on adding a 6-inch lift kit with BDS coil overs and upgrading to 24-inch wheels. For other mechanical upgrades, he plans to add a Wehrli built transmission package (for 750-plus horsepower), a fixed-vane turbo, aftermarket injectors and a boosted fuel pump. With the other supporting mods, his end goal with the truck would be around 750 to 800hp at the wheels, which is a 125 to 175hp gain from where it is now.

All performance upgrades aside, John also plans on adding a fifth-wheel hitch so he can travel across the country when the time comes. Although he feels that truck still rides and steers the way it did as a stock vehicle, the difference in pep is now quite noticeable.

“If someone were used to a stock one and got in this one and drove it, their first response would probably be, ‘Holy crap this thing scoots, LOL.’ I absolutely love where the truck is,” he says. “It makes a great daily driver and still does anything I need to do, but as all boys and their toys know, we are never done. I am not exactly sure what will be next, but my truck will never really be ‘done.’”