A brothers-built, 6.7L Power Stroke puller that’s intended to run neck-and-neck with the best in the business.
It’s hard to believe, but two brothers, working in tandem under the roof of a small steel shed in rural Missouri, have built one of the most competitive rides in diesel truck pulling’s Pro Street class. Josh Graver and his brother, Justin, both die-hard Ford fans, are campaigning the “Holler Hooker,” which boasts one of just two (that we know of) 6.7L Power Strokes in the 2.6 smooth bore category—and in 2024 the truck came into its own.
Thanks to a fine-tuned chassis, state-of-the-art turbo technology, and a battle-prepped engine with a solid fuel recipe, Josh collected a pair of wins behind the wheel of the ’11 F-350, including consecutive qualifiers at the Scheid Diesel Extravaganza. Better yet, with some of the most reputable names in the industry involved, plenty of future potential exists in the potent 6.7L platform. Look for the Holler Hooker to continue to claw its way to the top of the ultra-competitive 2.6 class in 2025.
Immediately apparent under the hood is the remote mount location of the turbo, made possible thanks to the handywork of Point Zero Fabrication. The engine is based on a 2020 model year 6.7L Power Stroke and sports a factory crankshaft anchored in place courtesy of a Maryland Performance Products girdle and ARP main studs. The stock stroke crank swings a set of Wagler billet connecting rods, fitted with factory steel pistons that’ve been thermal coated. A Stage 1 camshaft from RCD Performance controls the valvetrain. Over the winter, Josh plans to bolt the Power Stroke to an engine dyno for a bit of horsepower hunting. “I’m hoping there is another 40-50 hp in it somewhere that’s just been hiding behind the keyboard,” he told us.Building on the favorable flow the factory reverse flow cylinder heads bring to the table, Josh shipped them to Wagler Competition Products to be opened up. In Wagler’s care, they underwent port work to allow the engine to breathe as freely as possible at 4,000 rpm and beyond. The aluminum heads have also been machined to accept fire-rings (as has the block) and fitted with 120-lb valve springs. ARP head studs secure them to the block.A Hart’s turbo is a familiar find in the Pro Street Diesel Truck class, but this version of the company’s cutting-edge, ball bearing, 2.6-inch smooth bore charger is a tad different than the rest. In an effort to ensure the truck could spin out at the end of each hook, Josh chose a slightly smaller, 3.6-inch turbine wheel rather than the more common 4-inch version. On the compressor side, the Hart’s unit sports a billet wheel with a 66mm inducer. All piping, including a masterful set of exhaust manifolds and T6 collector, were fabricated by Shane Ferguson of Point Zero Fabrication. Heading down track, the 2.6-inch smooth bore turbo sends 48-50-psi of boost through a modified air-to-air Spearco intercooler.Partnering with S&S Diesel Motorsport, Josh’s 6.7L Power Stroke was equipped with one of the company’s popular DCR pumps. The direct, drop-in high-pressure unit sits in place of the factory CP4.2 at the front of the lifter valley and provides up to 25-percent more flow. “I wasn’t thrilled with a CP4.2 possibly taking out a $6,000 set of injectors,” Josh told us. “So, the DCR idea was born.” A bolt-in proposition, no tuning changes were required in order to run the DCR pump, and Josh believes it played a key role in the extra horsepower he picked up between 2023 and 2024.S&S fuel components continue up top, with a belt-driven, 12mm CP3. Combined with the DCR pump, ample rail pressure is always on tap for the injectors. Also built by S&S, the piezo electric units are fitted with 200-percent over nozzles that utilize the factory 8-hole design and spray angle. Proven Diesel’s Azraie Dumont fine-tunes everything on the electronic side by way of the factory Ford PCM. According to Josh’s best educated guess, the engine is currently turning out somewhere between 1,150 and 1,175 hp—not far off the pace of the engines powering the country’s top-running Pro Street trucks.A happy high-pressure common-rail engine is dependent on sufficient low-pressure fuel supply. For that, Josh relies on two FASS systems, one of the 220-gph variety and the other capable of flowing 240-gph. This arrangement, which locates both pumps in the truck’s weight box, provides each high-pressure fuel pump its own independent source of fuel supply. The unit that’s dedicated to the DCR sends 65 psi its way while the second FASS pump provides the CP3 a steady 15 psi. A Derale Performance fuel cooler is also part of the equation—and it’s also packaged within the weight box.Getting as much power to the ground as possible is left in the hands of a 6R140 TorqShift transmission. Built by the late Midwest Diesel & Auto, the six-speed automatic conceals Raybestos GPZ clutches, billet input and intermediate shafts, and a 3,000-rpm stall, triple-disc converter from Precision Industries, which Josh locks as soon as possible. Rock-solid reliable to date, Josh has racked up 65 trouble-free hooks on the TorqShift and told us he has no plans to venture inside it. Josh also disclosed that this season, pulling in Second gear, and on the high side of the transfer case, yielded the best results.You won’t find a Sterling in the rear of Josh’s F-350. Instead, the proven Dana 80—complete with Yukon axle shafts, a spool, and 5.13 gears—copes with the power dished out by the engine and the stresses imposed on it courtesy of the sled. Up front, you’ll find a Dana 60 plucked from a ’15 Super Duty. It was chosen for the heavier duty axle shafts and bigger U-joints Ford implemented that model year. A Yukon Grizzly locker and 5.13 ring and pinion make it just about as battle-ready as a Dana 60 can be.One of the biggest improvements the Holler Hooker saw for the 2024 season was the addition of this four-link suspension up front. Built by PMF Suspension, the beefy, long arm system settled down the truck’s front-end significantly, all but eliminating its previous wheel hop issues. Additionally, the four-link arrangement quelled the caster problems Josh was repeatedly facing. Up ahead of the Bilsteins positioned on each side, you’ll find a QA1 shock. The double adjustable QA1’s are used to fine-tune the factory coil springs, although Josh conveyed that the coils may be gone next year.Going aggressive, Josh runs a pair of Nitto Mud Grapplers up front. The extreme mud terrains measure 35×12.50R17LT, are mounted to 17×9-inch Ion wheels, and have anywhere from 17 to 30-psi in them depending on how loose or tight the pulling track is. At each end of the rear Dana 80, the popular Interco Trxus STS’s, also measuring 35×12.50R17LT, got the nod. The three stage sidewall (STS) all-terrains, which are required to carry most of the load from the sled, are typically aired up to between 45 and 50 psi.It’s all business in here. Nothing is for looks, aside for maybe the billet hand throttle from GP Diesel. The cab’s interior has been gutted for weight savings and only the bare essentials remain. On the pedestal that’s bolted to the transmission tunnel, a trio of GlowShift analog gauges are present, displaying the few key parameters Josh has a second to check in on before it’s go-time (engine oil pressure and supply pressure from each FASS system). Driving duties are conducted from an aluminum Kirkey Racing seat.Trust us, the Holler Hooker’s 4,000-rpm song sounds different than the rest of the competition in the Pro Street Diesel Truck class—even the other V-8’s. After adopting the strategy of leaving the line with slightly less rpm midway through the season, Josh saw instant success. On one occasion, he was even able to finish just six feet behind class front-runner (and 2024 PPL champion), Scott Barcus in the Cole Train Dodge.In addition to securing a win at his favorite track in Marthasville, Missouri in 2024, Josh finished first at a pull in nearby Palmyra. And that’s in addition to qualifying two consecutive days at the Scheid Diesel Extravaganza. Not bad for a home-built, Power Stroke-equipped Ford competing in the Cummins-dominated 2.6 category. Josh is especially grateful for the help he’s received from Renegade Diesel, S&S Diesel Motorsport, Jared Rice, and Patrick Marler in getting the truck to this level.
