GMC SIERRA 2500HD: BEAR EDITION

Words: Kristie Real

Photos: Brian McGee

Building rigs is never easy and the hardest part has to be the uncertainty of it all. A customizer doesn’t know going in if the build will take three weeks, six months or even a year. There’s no way of knowing how many challenges you’ll face, and little did Trent Clark know that his customizing journey would be way longer than expected…
If you have been to SEMA over the past few years, you have likely seen his beautiful 2007 GMC Sierra 2500HD beast of a machine that breaks all the rules when it comes to performance and appearance. What was supposed to be a moderate corporate promotional truck for his construction company in Calgary, Canada, escalated into an undeniable attention grabber for clients, requiring loads of time, money and patience. And when we say time, we mean it. While many builds take a few months and maybe a year, this one has been ongoing for eight years. Being in the construction business, something big real big and powerful was needed if it was truly going to be a promotional vehicle.
The truck was first leased as a stock 2500HD and the initial thought was to obtain a rig that would perform well and feature the ability to pull a heavy work trailer. To reach these goals, a 6” lift , custom wheels wrapped and bigger tires and fender flares were added for a more aggressive look. For power, a second turbo, head studs, mild ATS transmission, Edge monitor, straight-pipe exhaust, SSBC brakes, and 100-percent-over injectors were all added.
Just these upgrades alone drew attention when it arrived at work sites, but there was a catch and cost. With all of the extra horsepower, the engine died, which only meant a custom-built engine was now needed. SoCal Diesel was called in for a solution and a custom-built Duramax quickly followed, allowing for more air and fuel, in addition to a triple turbo setup, 2-stage NOS system, and a 265-GPH FASS system. What seemed like a good idea in being able to handle more power turned out to be a bit of a mistake, as the truck was not very driveable.
To fix this problem with the GMC, the truck was sent to one of the best in the industry when it comes to Duramax motors – Rob Coddens (“Idaho Rob”) of Adrenaline Truck Performance in Meridian, Idaho. The triple turbo setup was taken out in favor of a compound turbo setup consisting of 106mm and 68mm Garrett ball bearing turbos and the FASS system was upgraded to 220 GPH and the s. With Rob involved, the company once again had a streetable promotional truck, with testing on dyno using (pump fuel alone) it reached 1,246 rwhp and was not anywhere near reaching its full potential.
Not to be out done by power, the truck then received a powder coated 8” Bulletproof Suspension lift kit, American Force wheels, Nitto tires, custom side steps, a partial exterior wrap and a complete Hertz audio system. All seemed well until yet again the engine went boom…again (“Yes, again!,” he exclaims).
The GMC was then sent off to Curtis Halvorson of Extreme Engine Development in Calgary, Canada. With further mods to the already-built SoCal motor, a new animal was born. Yet again, this created another new problem for Trent and the GMC. This time, the ATS-built transmission could not be held together. Billet input, output, and intermediate shafts, along with a billet flywheel and with an oversized spring and Stage 6 PPE Clutch Pack were what many thought would be required. But that wasn’t the case and a series of transmissions were abruptly brutalized. Not to be denied, a solution was found – a Commercial Powertrain stepped up with a 2,000-hp transmission warranty utilizing their custom clutch kit and valve body.
Finally, everything was holding together when yet another disaster struck; white smoke and the smell of diesel fuel closed down a major street as a result of an injector, the block being dropped. Within two weeks of dropping the injector, the engine had a cracked block and broken crankshaft. Many would have thrown in the towel on the build by now (and Trent did have some serious reservations), but this was just another setup in the epic build.
Curtis Halvorson was once again called up to the game by stuffing into the LMM motor whatever he felt would result in it holding together. The fueling performance boost was done with the addition of a custom Dynomite Diesel Products (DDP) 275-percent-over injectors and a 12mm Exergy fuel injection pump to replace one of the stock CP3 units. The FASS system was once again upgraded to 260 GPH.
With power and performance finally fixed and ready to go, the only thing left to do was finally make it a show queen to be taken to shows and be loved by all. This was done via custom airbrushing by MOB Airbrush, a 12” Bulletproof Suspension lift, custom audio enclosure in the bed and many interior upgrades. The machined 30×16 Kompression Wheels set off it’s gigantic stance. Trigger Industries and Schultz Diesel Sports combined forces to create a one-off 18” air suspension along with and continual modifications to the interior by Trim Pro. With EPA shutting down ATPTrucks (“Idaho Rob”) Schultz Diesel Sports provided the final piece of the puzzle as they managed all of the tuning and build aspects, including all adjustments to the driveline (in conjunction with Driveline Specialist Inc.), transmission and suspension. After the long journey, the rig was finally complete and Trent relished in the outcome. He had waited years for the moment when it would be declared done and now takes pride in all the blood, sweat and tears put into this massive GMC build. “This truck is wild in every way,” he explains. “There’s no other truck in the world like it today.” And Trent wouldn’t have it any other way.