For far too many years now, Mopar fanatics have watched from the sidelines as LS guys have been swapping the modern GM power plants into everything from vintage Camaros to late model Mazda MX-5s. Sure, there’s been a few special builds out there which have featured the third-generation Hemi motors, but those projects have been largely relegated to pre-2011 motors, which do not utilize encrypted PCMs.

Even then, the swap entailed far more than just new motor mounts and a few wire splices, as the process of making the modern motor talk to vintage hardware wasn’t exactly elegant in its simplicity. But with Mopar Performance’s crate motor kits announcement at this year’s SEMA event the formula has changed substantially, and Dan Frazzini’s 392-swapped ’70 Plymouth AAR ‘Cuda tribute is among the first to benefit from FCA’s efforts to support this growing trend.

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Shown here post-transplant, Frazzini's pro touring Barracuda rides on 18-inch US Mag wheels wrapped in Hankook Ventus V12 high performance rubber. A comprehensive suspension overhaul comes courtesy of Hotchkis and includes shocks, front and rear sway bars, and torsion bars. Along with vastly improved road holding capability, these upgrades give Dan's 'Cuda its aggressive, hunkered-down stance.

“When I bought the car it had a 340 6-barrel, which had the ‘cool factor’ when I opened the hood, but it was a pain to keep tuned at the high altitude in Denver, and it was just not fast enough for me,” Dan explained. “I thought about stroking the 340 or another engine swap. I was watching some videos from SEMA looking for ideas when the Mopar announcement caught my attention. When I saw that they now offered a swap kit for the 392 Hemi crate engine designed for a classic Mopar, I knew that was the path I wanted to go down.”

“Our new Mopar Crate HEMI Engine Kits answer enthusiast demand for a relatively simple solution for plugging modern-day HEMI engine power into their classic Mopar rides,” said Mopar chief Pietro Gorlier when announcing the new kits in November. “The engine kits include the hardware to plant a 5.7-liter or 6.4-liter HEMI engine under the hood with the factory-backed confidence that comes when using Mopar parts. They also offer optional front-end accessory kits like power steering or even exhaust manifolds to make installation easier.”

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In the late 1960s, Trans Am rules specified that no motor could be larger than 305 cubic inches, which is the reason why both the original Boss 302 Mustang and Camaro Z/28 are equipped with unique high-revving small blocks. By 1970 the SCCA had loosen its rules a bit, allowing the 340 to be sold in the road-going version of the AAR while the race car motor's displacement would be reduced to 305 cubes. Like the 302 motors in the Ford and Chevrolet, the AAR 'Cuda's power plant was a stout piece considering its displacement, but its no match for modern engines like the 392 Hemi, both in terms of performance and reliability.

Factory-Backed Solution

Although the swap is still more involved than a typical LS project, Mopar’s involvement dramatically simplifies the process versus the old methods of transplanting modern Hemis into old school Chrysler vehicles.

For a number of years, the encrypted PCM of the 2011 and newer Hemi motors was a significant obstacle not only for engine swaps, but for modification in the vehicle that it was originally installed in. Initial efforts required swapping out those PCM controllers with earlier non-encrypted versions, but aftermarket tuners like DiabloSport have since released workarounds that are less invasive and costly.

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In the midst of rebuilding a 1971 Dodge Challenger, this '70 Plymouth Barracuda found its way into Frazzini's garage. It had just been through a comprehensive two-year restoration process when the previous owner passed away just a few months after its completion. The clean, as-new appearance comes from a Legendary Auto Interiors kit, while a Tuff steering wheel adds a subtle high performance look. It had been built as an AAR 'Cuda tribute car, but began life as a standard 318 Barracuda.

Mopar Performance goes a step further with this swap kit, including an unencrypted PCM along with the engine and chassis harnesses, accelerator pedal, and all the other incidental bits and pieces required to make the swap much more of a “plug ‘n play” proposition than it formerly was.

The crate motors are rated at 383 horsepower and 412 pound-feet of torque for the 5.7-liter Hemi and 485 hp with 472 lb-ft for the 6.4-liter 392 Hemi that Dan opted to use in his Barracuda.

Previously purchased 2014-and-newer 5.7 and 6.4-liter motors will work with these swap kits as well. While the kits are designed and optimized to work with a manual transmission, automatic transmissions including the Torqueflite 727 and 904 can be adapted to work with the kit too, as Dan has done here. The Gen III Hemi shares the bolt pattern with the LA engines, so the swap was straightforward, only requiring a new flexplate.

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While it's feasible to do this swap in a home garage, access to a lift will make the job much easier. Although there's some firewall modification involved to make everything fit, once the 6.4-liter Hemi is in place, it looks right at home under the hood of this Barracuda, even though more than four decades separates the birth of the car and the modern Hemi. "Expect the unexpected and budget accordingly" are pieces of advise offered by Frazzini that one would be wise to keep in mind when considering a swap like this.

“When I purchased the Barracuda, it already had a recently rebuilt 727 and a brand new rear end with 3.55 gears, which were perfect for me,” Dan says. “The car was originally a garden-variety 318 car built in the LA assembly plant, which made it an ideal candidate for this swap, since I prefer to modify my vehicles to run the way I want them to run.”

Modernizing the AAR Formula

Back in 1970, Chrysler was keenly interested in getting their new E-Body vehicles into the production racing classes where the Mustang, Camaro, Javelin and other performance coupes had been mixing it up for years. Homologating the car for the SCCA’s Trans Am series meant offering a road-going package similar to the race car, resulting in the Plymouth ‘Cuda AAR and the Dodge Challenger T/A.

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As cool as the 340 six-pack motor is, it's hard to deny the fact that keeping those carbs happy requires regular stints under the hood dialing them in. By contrast, the fuel injected Gen III Hemi does essentially all of its tuning on its own, functioning much like any other modern motor. That drivability along with the 150 or so horsepower upgrade it provides (even more if you consider the differences in how HP now versus when the 340 was in production) was reason enough for Dan to embark on this transformative swap.

Instead of making straight line performance the top priority, these homologation specials focused on balanced dynamics with upgraded suspension and brakes, along with a light, high-revving small block V8 installed in the engine bay. That package had a similar goal to Dan’s pro-touring project, so the marriage of aesthetics here plays out extremely well.

Dan told us, “I would never do this to a real AAR as those are too valuable and rare. But this being a 318 car, then with a 340, it was the perfect car to do a 392 swap in. The previous owner also added the white strobe stripe and the AAR front and rear spoilers.”

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With the Hemi's drive by wire system, a modern accelerator pedal is required for the swap so that throttle position can be relayed back to the engine. You can see where Dan has modified the pedal to shorten it for a better fit in the cabin.

“I wanted a more aggressive pro-touring look to go with the AAR spoilers and strobe stripe,” he told us. “So I swapped the 15-inch Rallye wheels with the US Mag 18×8 and 18×9.5 wheels with 245/45/18 and 275/40/18 Hankook tires. To gain a little performance and improve the sound I swapped in a custom x-pipe with Magnaflow straight mufflers and kept the AAR-style side exhaust. The next step was to improve the handling, so I upgraded to Hotchkis suspension components with 1.10-inch torsion bars, added a rear sway bar, and installed Fox shocks with adjustable fronts. I also installed a Tuff steering wheel for better control.”

Along with the significant upgrade in power over the 340 that the Barracuda had when Dan originally acquired the Plymouth a few years ago, the modern 392 Hemi makes the car substantially more drivable. “The 340 6-barrel was a strong runner, but I wanted more reliability to go on a long road trip. I have a ’68 Charger with a 505 ci stroker, so I already have the big street brute,” he explained.

“For this project I wanted the ‘Cuda to have the convenience of a modern car paired with the cool factor of a ’70 Cuda. As Mopar was announcing the new crate engines and kits at SEMA, I was on the phone ordering one. However, my eagerness and lack of research led to many lessons learned.”

While the crate engine program and swap kit enable enthusiasts to do this swap with far more ease than before, it’s still an involved process that includes fabrication and modification to the firewall and engine bay of E-Body Mopars, so a comprehensive set of tools and fabrication skills are a requirement if you’re planning to take on this project yourself – and a lift is highly recommended.

“I called my good friend and reserved a spot in his shop for the engine swap. We completed the entire swap in just 5 days,” Dan reports.

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The eye catching design of the third generation Barracuda is one of the most instantly recognizable shapes from the original muscle car era. Within the Barracuda roster, the AAR 'Cuda is arguably the best-looking variant of the bunch, distinguished by its black NACA-ducted hood, side pipes, front and rear spoilers and unique strobe stripe package to go along with its high-winding small block and upgraded handling components . The package lends itself quite well to pro touring modification, and that goal of improving vehicle dynamics with modernized hardware jives particularly well with the original mission of the AAR.

The results speak for themselves – Dan’s ‘Cuda now has the added reliability and everyday drivability of a modern muscle car coupled with the head-turning good looks of the classic E-Body. And that’s to say nothing of the big upgrade in both output and fuel economy that the 392 provides. With Mopar Performance now offering swap kit solutions to builders like Dan, we expect to see a lot more of these killer modern Hemi transplants in the coming years.

See more of Dan’s beautiful AAR ‘Cuda tribute and his swap to the modern 392 Hemi in the gallery below. It was a lot of work, but Dan stated that Mopar’s crate Hemi kits, and a little bit of elbow grease and patience made it all worth the effort. We agree, the car is a great tribute, and now it’s a great driver, too.