For nearly half his life, Mark Dudley Jr. has been behind the wheel of his ’74 Duster. He’s raced it since he was 15, built it himself, and lived through every mechanical iteration of a racecar it’s had. Today, it sports a Blackbird Performance Race Spec 700 for power, a Gen 3 HEMI engine that’s transformed his program and rewritten what reliability and performance from a modern platform can look like in grassroots bracket racing.
“It’s a 6.4-liter Gen 3 HEMI — it’s got stock heads, better seats, CNC work, about a .635-inch lift hydraulic roller, stock rockers, stock Hellcat lifters, Wiseco pistons, all-forged rods, and a stock crank,” Dudley explains. “It makes right at 720 horsepower.” The combination, built around the same BGE block used in factory Hellcat applications, is mated to a 727 Torqueflite transmission and a Dana 60 rear with 4.56 gears. It’s got a 30×9 drag radial out back and has been 6.04 at 114 in the eighth, and 9.50 at 140 in the quarter.”
That performance comes from a car that’s about as honest as they come, with all original steel and stock suspension. “It’s all steel, all original floors,” he says. “Stock front suspension with torsion bars, single-adjustable QA1’s up front, and CalTracs with split mono-leafs and Rancho nine-way shocks in the rear. It’s super simple.” At 3,200 pounds, Dudley’s Duster moves with the urgency of a lighter-weight car.
But it wasn’t always that way. The Duster originally had a 418 cubic-inch small-block Mopar, a J-headed 340 that, at its best, went 6.59 at 103 in the eighth. “It was a good motor that I ran forever, but it finally gave up,” he says. “When it broke, it broke the rearend, the transmission, and pretty much everything else. I’d wanted to do a Gen III HEMI for a long time, but nobody around here had done it yet.”
That changed at the Rockingham Mopar Show, where Dudley met Geoff Turk of Blackbird Performance. “I’d been following what Geoff was doing,” he recalls. “The Gen III is a direct small-block replacement, and that’s what sold me. With a traditional small-block Mopar, you can only go so far before you start splitting cylinders or spending crazy money on blocks that aren’t even that great. The Gen 3 HEMI just bolts straight in. And when I say bolts in, I mean bolts in — no header dents, no fitment issues, nothing. I used TTI headers and motor mounts, and it went right in the car like it was made for it.”
That ease of installation was matched by the simplicity of the setup process. Dudley’s Duster runs on methanol with a Get’M carburetor and Blackbird’s Afterburner ignition system, which comes standard on every Race Spec 700.
“I’d never had any electronic ignition in the car, so I was nervous about that controller. But it’s the easiest thing I’ve ever wired in my life; it’s literally self-explanatory. You’ve got a couple wires, one hot all the time, one switched, a ground, and that’s it. The whole harness is one piece. From the time I opened the box to having it running was 15 minutes. We built the whole car in a week, the motor, transmission, rear end, everything, and it’s been flawless ever since.”
“Mark’s car went together flawlessly,” Turk shares. “At about 11 o’clock one night he, his dad, and grandpa decided to wire the ignition. None of them had ever wired an electronic control system in their life. I told them, ‘If you get it started tonight, call me.’ At 12:45 a.m. I got a video of the engine running. Three wires, fired right up—that’s how easy it’s supposed to be.”
To say it’s been flawless is not an exaggeration. Since the swap, Dudley has logged roughly 320 passes. “I’ve changed the oil twice,” he says. “About every 125 runs. I’m running it on methanol with a Get’M 1000 cfm twin-blade carb, and it’s been perfect. I don’t even have a transbrake or a two-step, I’m just foot-braking. It’s simple and deadly consistent.”
“There’s nothing exotic about this combination,” Turk tells us. “It’s a stock 6.4-liter Gen 3 HEMI foundation with forged rods and pistons, our valvetrain recipe, and a carburetor on top. It’s inexpensive, simple, and very durable—exactly what bracket racers have been asking for.
The results speak for themselves. Dudley’s been in 14 finals this season alone, finishing second in points at Piedmont Dragway in 7.49 Real Street and top five in Outlaw Door Slammers. He double-enters regularly, sometimes running as many as four classes in a weekend between Piedmont, Farmington, and Mooresville Dragway. “The car’s been absolutely nasty. The only time it wasn’t perfect was at Bristol, but that was on me; the air swings are big there and I didn’t have it lean enough. Otherwise, I could unload it right now and bet a hundred bucks it’ll run a 6.10 or 6.11. I don’t even really need a time run anymore,” Dudley explains.
That level of consistency has made the car a highly dependable bracket machine. Dudley attributes it to the inherent design of the Gen 3 HEMI and Turk’s Race Spec program. “It’s just maintenance-free. Geoff told me to race it and if something breaks, we’ll find the weak link. Well, we haven’t found one yet. I’ve never had the valve covers off. I’m going to pull them this winter just to check springs, but it hasn’t lost a lick of e.t., there’s no leaks, no hiccups, no drop in performance.”
Dudley has nearly 15 years of seat time in this same Duster — and now, with a bulletproof 700- plus-horsepower HEMI under the hood, it’s faster and more consistent than ever. “This thing’s been a godsend,” he says plainly. “It’s the most consistent, reliable car I’ve ever had. It’s taken everything I’ve thrown at it.”
“The Gen 3 HEMI deserves more credit than it gets,” Turk says. “Put it in an A-body like Mark’s Duster and it’s a light, efficient, fast package. But it works in B-bodies, dragsters, super-class cars, anywhere you want 700 to 900 horsepower naturally aspirated. It’s a versatile, reliable, cost-effective powerplant that belongs in a lot more race cars.”
With 320 runs and counting on a host of stock parts, Dudley’s Duster proves exactly what Blackbird set out to accomplish with the Race Spec 700: an affordable, durable, and highperforming Gen 3 HEMI that racers can install, wire, and go to war with. It’s a 3,200-pound steel-bodied bracket car that runs 6.0s on repeat and needs little more than fuel and oil.
As Dudley sums it up, “I’ve been in the finals more times this year than in any other season I’ve raced. I’ve changed oil twice. I’ve never pulled a valve cover. And it runs exactly the same today as the day we fired it up. You can’t ask for anything more than that.”
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