No Hemi Needed: The LS-Powered Eight-Second Plymouth Sport Fury

10 min read

No Hemi Needed: The LS-Powered Eight-Second Plymouth Sport Fury

10 min read

Stephen Dupuis’ life-long passion for speed has always motivated him to find ways to go faster. Now retired, the Port Neches, Texas resident says that his formative years were largely spent trying to figure out how much spray his LT1-powered ’73 Nova could handle without leaving a trail of parts at the starting line.

“When we were running nitrous in the late 70s and early 80s, nobody really knew what they were doing,” he says with a laugh. “Back then, horsepower wasn’t as easy to come by as it is today, so we were doing whatever we could. We didn’t heat the bottles up, look at pressures, or have pills to adjust. We didn’t even pull timing. We just knew that it worked!”

Dupuis’ Nova became a formidable presence in the local street scene, but the responsibilities of adult life eventually forced him to put his racing ambitions on hold. Retirement has freed up his schedule a bit, though, so Dupuis has gotten back into the swing of competition. He acquired a ’72 Chevrolet Nova in 2016, and with motivation from a nitrous-fed 434ci small-block, he has been campaigning the car in the Index Outlaws series at his local track, Evadale Raceway. While that has largely satiated Dupuis’ need for speed, in recent years he’d been itching to branch out and build something a little bit more potent.

“I had bought this LSX454R crate motor from a friend who had planned to use it for one of his projects, but then decided to go in another direction,” he explains. “So I was in the market for a roller, and fortunately for me, this ’62 Plymouth Sport Fury happened to be just a few miles away in the next town over. It was built by Larry Thomason, who’s been racing for decades. I’ve known him for more than twenty years through our business connections, and one day he invited me over for coffee at his shop. I happened to see the car there, and I just immediately fell in love with it.”

Although it wasn’t a roller – Thomason had dropped a 550 cubic-inch Mopar big block into the Plymouth’s engine bay and hooked it up to a Lenco three-speed gearbox – it was a project that had been left on the back burner for a while. Dupuis decided to see if they could work something out.

“This was going to be more of a purpose-built race car, but the project ended up taking so long that it got to the point where it was becoming difficult for Larry to get in and out of it,” Dupuis says. “And he still has another ’62 Sport Fury that he’s been driving his since high school days, so I think he was ready to move on from this one.” After some deliberation, Thomason agreed to sell Dupuis the car without the Mopar big-block last year, and with Thomason’s blessing, Dupuis soon set to work getting it moving under LS power.

“The headers were the biggest challenge,” he tells us. “It’s a tube-chassis car, so I needed to create a custom set, and it was the first time I’d done something like that with a kit here at my shop. The rest was little stuff, like building a motor plate for the LSX, trimming the firewall, and swapping out the manual fuel pump for an electric one; he had been planning to run alcohol, and I’m running gas.”

The Plymouth’s 770hp GM crate engine is a stout piece that sports an iron block and a forged rotating assembly, along with a mechanical roller cam, six-bolt LSX DR cylinder heads, and a high-rise, open-plenum intake manifold. An 1150-cfm Holley Dominator carburetor is mounted on top, while an MSD 6014 LS ignition control box handles the spark.

In contrast to his Novas, Dupuis isn’t planning to run any power adders with the LSX – for now, anyway. “When I bought it, it had been plumbed for two 300hp fogger kits, and I actually took all of that off,” he notes. “I’m planning to run the car naturally aspirated a 5.80 index. Nitrous might be in the future, though.”

The grunt makes its way to the pavement through the aforementioned Lenco three-speed transmission with a Bruno Drive and a Dana 60 rear end with 4.11 gears. The Plymouth’s 7.50-certified tube chassis, meanwhile, is based off of a Jerry Bickel design and is equipped with a strut suspension up front and a four-link at the rear.

Much like the rest of the car, the Sport Fury’s interior is all business: A Racepak digital display provides Dupuis with all of the real-time vitals and the requisite safety gear is on-hand to keep him protected. Custom touches, like the fabricated pedal assembly, also add a bit of visual flair to the purposeful cabin.

The car’s distinctively sinister aesthetic is owed in part to its sharp Weld Racing wheels, massive hood scoop, and monochromatic black paint, but it’s the top’s three-inch chop that really sets it apart from the crowd. “Larry had planned to run it in NHRA Super Gas, and he had to car set up to be as low as the rule book would allow,” he says. “The rear quarter panels are original, though – they’re not flared out at all. It’s really the top that changes the look of the car.”

Even though the team is still getting the car dialed in, Dupuis has already recorded personal bests of 8.80 at 155 miles per hour in the quarter mile and 5.60 at 124 mph in the eighth. “We haven’t really started racing it yet – we’re still working a few bugs out. The series I compete in has already started and we’ve missed a few races, so for the most part we’re going to spend this season testing and getting ready for next season.”

While he’s focused on getting the car dialed in for the kind of consistent, repeatable performance that index racing demands, Dupuis says he may also do a small tire setup down the road. “I’ve kicked around the idea – there are a lot of small tire events around here. And at about 2150 pounds, the car is a lot lighter than people think it is.”


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