BLACK MENACE

AN 800HP LBZ DURAMAX BUILT TO DO ONE THING—AND ONE

AN 800HP LBZ DURAMAX BUILT TO DO ONE THING - AND ON THING ONLY

If you’re raised on a farm, you’ll likely grow up to be a farmer. It’s just what you do. And if you farm in America’s Heartland, chances are pretty good you’ll take an interest in truck and tractor pulling. Things were no different for west-central Illinois native Nathan Beard. In his neck of the woods, the 8,500-pound Work Stock diesel truck class is all the rage. It consists of former work trucks, farm trucks, and daily drivers that have been transformed into highly modified versions of their former selves. Because of class rules, they’re over-fueled and under-turbo’d, yet many of the trucks in this field have no problem making 800 hp or better.

WORK TRUCK TO WORK STOCK

While watching the local Work Stock class take off in popularity was fun to watch, Nathan wanted to get in on the action himself, and by 2018 he was finally ready. To do it, he would simply “repurpose” the 150,000-mile ’06 Chevrolet Silverado 3500 HD he had purchased for farm use. After a season of getting his feet wet in the sport, a host of changes were made over the winter. Then he came out swinging in 2019 with a strong, Second Place finish at the truck’s first hook. The 312-foot ride he and his Chevy made (at nearly 30 mph) definitely got our attention, so we moved in for a closer look…

DERMODY-PREPPED DURAMAX

Knowing the factory LBZ Duramax would never survive the type of abuse it was destined to see, Nathan dropped the engine off at Dermody Diesel Performance in Murrayville, Illinois. Now, an externally-balanced crankshaft (anchored in place with ARP main studs), forged-steel rods

from Wagler Competition Products, and Lb7-style Mahle cast-aluminum pistons are ready to absorb the kind of cylinder pressure it takes to win. For good measure, one of Wagler’s pinned oil pumps also made the cut. Up top, a pair of Wagler-ported factory heads—equipped with dual valve springs—usher more air in-cylinder.

BUILDING BOOST

With fixed geometry turbos ruling the roost in today’s turbo-limited truck pulling classes, Nathan knew from the get-go that a Vgt-based charger was out. Meeting local Work Stock rules, he sourced an S366 SX-E from Dermody Diesel that’d been treated to a few tweaks in order to improve airflow. The charger mounts to a T4 twisted pedestal from Wagler, which also facilitates the use of Wagler’s one-piece street intake in place of the original Y-bridge. Hot and cold-side intercooler pipes from HSP Diesel route boost through a Mishimoto intercooler, while PPE exhaust manifolds and up-pipes help drive the turbocharger.

S&S FUEL, CTT TUNING

A set of 100-percent over injectors and a 12 mm CP3 from

S&S Diesel Motorsport mean there is no shortage of fuel on tap for the hungry Duramax. The OEM location stroker pump gets its low-pressure fuel supply from a 165-gph Airdog II-4G system mounted along the frame rail, and the lift pump pulls fuel from an RCD Performance sump installed in the factory tank. EFI Live wizardry from the folks at CTT Tuning brings a steady 26,000 psi of rail, just under 50 psi of boost, and at least 800 hp into the equation.

ALL-BILLET ALLISON

Making the six-speed Allison 1000 structurally sound entailed all billet shafts, a billet P2 planetary and C2 hub, Suncoast-sourced clutches and steels, and a Q model torque converter from Goerend Transmission. The billet stator, triple-disc unit’s high stall speed means Nathan can leave the line with a torrent of boost built up. And thanks to having plenty of horsepower on tap, Nathan’s bad-in-black

“NATHAN’S BAD-IN-BLACK CHEVY CAN CARRY 4,100 RPM DOWN TRACK.”

Chevy can carry 4,100 rpm down track, even in Fourth gear and 4-Lo. An Alli-locker from Fleece Performance Engineering allows him to lock the converter as soon as rpm allows, and then unlock it near the end of the track.

ROCK-SOLID, FROM TOP TO BOTTOM

Beyond the horsepower-making recipe, the truck’s suspension and axles have been optimized for surviving their battles with the sled. Front-end downward suspension travel is essentially non-existent, Cognito Motorsports’ extreme tie rods and center link eliminate toe-in, the AAM 9.25 has been treated to Tufshafts and a locker, and the AAM 1150 out back features DHD gun-drilled axleshafts, a full spool, and an LPW Ultimate differential cover. All of the above makes it possible for Nathan to drive his LBZ like he stole it, without fear of breaking it—and the end result is impressive. Of all the Work Stock trucks we’ve seen over the years, Nathan’s may be the fastest. Trust us, if you see his black dually being hauled into your county fair, there’s a good chance it’ll be taking home first-place money.

An Alli-locker from Fleece Performance Engineering puts precise control over torque converter lockup in Nathan’s right hand. Shortly after leaving the line, and when rpm begins to climb, Nathan locks the converter clutch and doesn’t unlock it again until the end of the track.

Built to (hopefully) never break, Dermody Diesel put together a killer Allison to back up the potent engine. A host of billet-steel hard-parts includes the input, intermediate, and output shafts, along with a 6-pinion P2 planetary and C2 hub. Suncoast clutches, steels, and some proprietary valve body mods top things off. A high stall, Q model triple-disc converter, complete with a billet stator from Goerend Transmission, affords Nathan the ability to leave the line with plenty of boost on tap.

Fuel makes its way toward the Airdog system via this sump from RCD Performance. Installed at the lowest point in the factory tank, it features a ½-inch supply port, a ½-inch return port, and a stand tube on the return side to keep the diesel feeding the lift pump separate from the aerated fuel returning to the tank.

With an injection system composed of 100-percent over injectors and a 12 mm CP3 from S&S Diesel Motorsport, a 165-gph Airdog II-4G system was chosen to handle low-pressure fuel delivery. To feed the 46-percent larger CP3 as much fuel as possible, Nathan keeps supply pressure set between 12-to-14 psi instead of the 8-10 psi you typically see in Duramax applications.

Upgraded to survive the worst of the worst in truck pulling, the rear AAM 1150 has been graced with gun-drilled, 38-spline axles from DHD, a spool, and an ultimate differential support cover from LPW Racing Products. On the other side the differential, you’ll find a one-piece steel driveshaft from Acme-decatur in place of the factory two-piece unit, along with one of DHD’S billet rear yokes.

 Once upon a time, Nathan managed to bend a set of One Up Offroad’s long-gusset adaptable traction bars. After being told he was one of only two truck owners to ever do that, the company sent him a replacement set with chromoly tubing. So far, these bars have had zero problems keeping the beefed up AAM 1150 in place and the rear duals digging.

 Looking at the truck’s IFS from the rear, you can see that the factory bump stops are gone and 2-inch blocks are positioned between the Rough Country rear cross member and the control arm. With these blocks in place there is no downward travel. Only upward movement is possible during the course of a pull, but only enough travel to optimize the CV angles without sacrificing the truck’s hitch height out back.

As you can see, Nathan is still running the factory AAM 9.25 Ifs—though it’s been upgraded considerably. Reinforcements and traction enhancements include Cognito Motorsports’ extreme tie rods and straight center link, Tufshafts from Fleece Performance Engineering, a welded differential (a.k.a. Miller locker), and RCV Performance’s Ultimate IFS CV axles. But don’t let the CV shaft angle shown here fool you. When the truck is on the hook the front suspension unloads, and both CVS operate in a perfectly straight line.