This 1972 Dodge Challenger Only Made 240 Horsepower From the Factory — Car Craft Just Gave It 807

A 1972 Dodge Challenger arrived during the weakest years Detroit’s muscle cars ever saw, topping out at 240 factory horsepower with no Hemi in sight. Car Craft’s revived build series just swapped in Mopar’s 807-horsepower Hellcrate Redeye, the same crate engine Dodge sells over the counter. The bigger challenge wasn’t the engine itself, but getting a car never designed for fuel injection to survive it.

When Dodge built this Challenger in 1972, Detroit’s muscle car era had already been gutted by emissions rules and insurance surcharges — the 426 Hemi was gone, the 440 Six Pack was gone, and the best engine you could check on the order form was a 340 V8 rated at a modest 240 horsepower. Car Craft, the legendary tuning magazine reborn as a build series on MotorTrend, decided that math needed fixing five decades later. Hosts John McGann and Kevin Tetz pulled a real 1972 E-body into the shop and dropped in Mopar’s Hellcrate Redeye — the same supercharged 6.2-liter HEMI crate engine Dodge sells over the counter rated at 807 horsepower. The catch: a car this old was never designed to run electronic fuel injection, let alone survive the torque of a factory Hellcat powerplant. What follows isn’t a typical restoration — it’s a rescue mission for a Challenger that rolled off the line at the worst possible moment in muscle car history.

Car Craft Returns to Fix What the 1970s Broke

Car Craft spent decades as one of the most trusted names in print for hands-on engine builds and drag-strip know-how before folding as a magazine. Its revival as a MotorTrend video series brought back two people with real credibility in the space: John McGann, a longtime Hot Rod magazine editor, and Kevin Tetz, a veteran builder known for his no-nonsense approach to swaps. Viewers who remembered the original Car Craft showed up in force in the comments, several calling out how much they’d missed the brand and how validating it felt to see it return to a genuine wrench-turning project instead of a lifestyle segment.

This first episode focuses on the single biggest decision in the build: pulling the numbers-matching low-compression 1970s drivetrain and mounting the Hellcrate Redeye in its place. The team walks through fitting the crate engine in the factory engine bay, addresses why the stock fuel system can’t feed a supercharged HEMI, and sets up the framework for the transmission and fuel system work that carries into the next episode. It’s less a highlight reel than a genuine build log, which is exactly the tone longtime Car Craft readers said they wanted back.

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Rather than cramming the whole project into a single video, the series stretches the build across multiple episodes, each tackling one system at a time. The engine swap covered here is followed by a second episode dedicated to sorting out the transmission and fuel system, and the build eventually works its way back to the rear suspension to make sure the chassis can actually put 807 horsepower to the ground without folding under itself. That pacing gives viewers a real look at how much work goes into a swap like this beyond simply unbolting one engine and bolting in another.

The 1972 Challenger Arrived at Detroit’s Lowest Horsepower Point

The timing of this particular Challenger’s original build makes the swap sting a little more. By 1972, insurance premiums on muscle cars had spiked so high that automakers were quietly walking away from big horsepower, and new SAE net power ratings — measured as installed in the car rather than on a stripped-down test stand — made every number on the spec sheet look smaller overnight. Dodge’s engine lineup for the Challenger that year shrank to three choices: a 225 cubic-inch slant-six making 110 horsepower, a 318 V8 rated at 150, and a 340 V8 topping out at 240 horsepower. A year earlier, in 1971, a Challenger buyer could still check a box for the 426 Hemi and drive away with 425 horsepower. By 1972, that option didn’t exist at any price.

That drop is why this generation of Challenger has such a complicated reputation among collectors. The body and chassis are unmistakably the same first-generation E-body that carried Hemis and Six Packs just a couple of years earlier, but the engine bay tells a very different story — one of an industry retreating from performance just as fast as it had chased it in the late 1960s. Cars like this one are often the most affordable way into an original E-body, precisely because the factory drivetrain never lived up to the body’s reputation.

That gap between what the car looks like it should do and what it was actually capable of doing from the factory is exactly what makes it such a compelling swap candidate. Instead of restoring a low-output 340 back to its original spec, Car Craft treated the shortfall as an opportunity. A stock 1972 Challenger 340, even with the factory’s four-speed and performance axle package, was looking at a 0-60 time in the neighborhood of seven seconds by period-correct estimates — respectable for the era, but nowhere close to what the Hellcrate now sitting in its engine bay is capable of producing once the supporting systems are finished.

Why the Hellcrate Redeye Swap Actually Works

Mopar’s Hellcrate Redeye isn’t a modified Hellcat — it’s the genuine factory engine, sold as a complete 6.2-liter supercharged HEMI assembly rated at 807 horsepower and 717 lb-ft of torque on 91-octane pump gas, running 14.5 psi of boost through its 2.7-liter supercharger and a 9.5:1 compression ratio. It ships with the water pump, oil pan, intake manifold, throttle body, injectors, and coil packs already in place, which is exactly why crate-engine swaps like this one have become popular with builders working on cars that were never meant to carry this kind of output.

The complication is that a 1972 E-body was built for a carburetor, not electronic fuel injection, so the team had to figure out how to convert the factory-style fuel tank to safely feed an EFI system under boost. The build also pairs the Hellcrate with a manual transmission, a new driveshaft, and a fresh dual-disc clutch rather than leaning on a factory automatic, and a reprogrammable ECU is going in to make sure the engine is tuned to make full power rather than a detuned fraction of it. None of that is a bolt-and-go job, which is exactly why it’s stretched into a multi-episode build rather than a single video.

Swaps like this one have become one of the more popular paths for owners of affordable, lower-trim classics who want modern performance without cutting up a numbers-matching Hemi car that’s worth preserving in original condition. Because the Hellcrate ships as a complete, drivable assembly rather than a bare block, a shop with the right fabrication skills can drop it into almost anything with enough room in the engine bay — which is exactly why a 1972 Challenger that once sold with a 240-horsepower ceiling has become a solid candidate for one of the most capable engines Mopar has ever sold to the public.

Watch the full video above and let us know your thoughts in the comments.