Possessed

The Road Was Long, But This 1,000HP LML Was Meant To Be

Ups and downs are part of any major automotive undertaking. However, some projects seem destined to fight you every step of the way. The latter certainly appeared to be true for Cory Jarriel and his LML Duramax. At every turn, the truck seemed to have different plans than he did. First, the truck fell off his two-post lift. Then, after considerable body work, came the electrical fire under the hood, followed by a factory connecting rod vacating the block. Then, once the new engine was in, the supposedly-built Allison sidelined the truck in less than 4,000 miles. Throughout each setback, Cory—who has personally undergone two open-heart surgeries—kept his head-up and ultimately persevered. His reward? A show-ready (and reliable) ’13 Silverado 2500 HD packing four-digit horsepower and more than 2,100 lb-ft of twist.

The Wagler Touch

When it came to the new LML (block and all), very few stones were left unturned. While Cory didn’t opt for a girdle or billet main caps, he did enlist Wagler Competition Products to build his Duramax. The rotating assembly consists of an externally balanced Callies forged-steel crankshaft, its mains secured via ARP studs, Wagler’s forged-steel rods, and fly-cut Mahle Motorsport cast-aluminum pistons. Valvetrain upgrades include Wagler’s alternate firing order cam, chromoly pushrods, and dual valve springs, with the heads being fastened to the block by way of ARP head studs. A Fluidampr, Sun Coast billet flex plate, and a pinned oil pump from Wagler also made it into the build.

S369/S480 Compounds

In his quest for a set of compounds that would support 1,000 hp at the wheels, Cory settled on a system from Screamin’ Diesel Performance. The arrangement locates a T6, billet compressor S480 and its corresponding piping on the passenger side of the engine, and replaces the VVT in the valley with a T4 S369 SX-E. High-flow exhaust manifolds and stainless steel up-pipes from PPE help drive the S369 efficiently, while 3-inch hot and cold-side intercooler piping, a Mishimoto intercooler, and a 3-inch Y-bridge open up flow and cool off the air on the intake side.

Four-Digit Fueling

Bringing plenty of fuel to the party, Cory sent the stock piezo injectors up to Exergy Performance to be transformed into a balanced set of 100-percent over units. To guarantee the rails never run dry, he elected to run two high-pressure fuel pumps. And thanks to ATS Diesel’s twin fueler injection pump system, a belt-driven CP3 shares fuel pressurizing duties with a CP4.2 mounted in the stock location. A Fuelab Velocity 200-gph lift pump and  -inch fuel lines are responsible for maintaining 8-psi of low-pressure fuel supply for the CP3 and CP4.2 to use. Fine-tuning of the potent injection system is accomplished through the use of EFI Live software.

Billet Allison

After his first “bulletproof” transmission self-destructed in short order, Cory made sure the next Allison build was executed with the best parts on the market. Billet input, intermediate, and output shafts, a billet C2 hub, competition frictions and steels, and a billet stator triple-disc converter from Diesel Performance Converters all made the cut, along with Goerend Transmission’s billet PTO covers, which improve lubrication of the C3 clutches. Extra fluid capacity comes in the form a Mag-Hytec deep transmission pan. The latest reinforced version of his six-speed automatic has proven much more reliable, which, in passing 2,170 lb-ft of torque on to the rear wheels, is saying something.

Curb Appeal & Steering Upgrades

Cory’s Silverado gets its height from a McGaughy’s suspension lift, which provides roughly 9 inches of added elevation up front and 7 inches in the rear. Fox 2.0 remote reservoir shocks (four up front and two in the rear) aid ride quality, and Cognito Motorsports’ alloy series tie-rods and idler and pitman arm support kit reinforce the steering system. Cosmetically, the truck wears the factory Mocha Steel metallic paint, but Cory knocked down some of the shine with satin clearcoat from Vintage Flatz. To avoid the inevitable rock chips that come from running 16-inch wide wheels and large void mud terrains, the rockers were coated in Line-X, along with the sideview mirrors, hood louvers, and grille.

The Payoff

It might’ve taken Cory longer to reach his goals than he would’ve liked to, but with the truck running strong and reliably with 1,000-rwhp on tap that’s all behind him now. “I’ve raced an AMG E 63 S and Nissan GT-Rs and won,” he told us. “That’s the fun part about all of it. No one ever expects a big, heavy diesel to beat them.” Tens of thousands of other truck owners, including us, would agree. The diesel thing isn’t the cheapest or easiest hobby to be involved with, but once you get the right combination of parts together it can be one of the most rewarding.

“I’ve raced an AMG E 63 S and Nissan GT-Rs and won.”