Every once in a while, you see a car that makes you stop in your tracks. It could be the beautiful chrome brightwork, or the massive rear tires, or the stunning engine bay. Cars often with check a few of those boxes, but Kenny Matlock’s 1968 Plymouth Road Runner checks every one. It’s hard to define the overall build of this Plymouth. From a distance, it looks like a Pro Street build with the insanely huge rear tires, but with its stance and wheel size, maybe it fits more into the Pro Touring category? Whatever the case, it is incredible.

Kenny’s dad bought this car brand new in 1968 in the Florida Keys. As a kid, Kenny rode everywhere in this car. A large portion of his childhood memories involved this exact car. His dad was as big of a gearhead as him and he daily drove this beautiful Mopar until 2002. Dear ol’ dad never babied it and drove the Road Runner like he stole it every time he was behind the wheel.

Kenny and his dad decided they wanted to build the car into something more, so they embarked on a 7-year-long project in his dad’s one-car garage to build this car into something wild. They used a second-generation Dodge Viper as a base and built a custom tube chassis out of it to fit the Road Runner. In doing this, they had to narrow the chassis to fit the Road Runner. The front suspension has been narrowed four inches total and the independent rear suspension was narrowed 11.5 inches to allow for a huge lip on the rear wheels.

We weren't joking when we said, "huge". The rear wheels are 20x15 three-piece Billet wheels wrapped in 29x18x20 rubber.

You start to understand why it took 7 years to build it just by hearing the necessary modifications to make the Viper chassis work. Custom sway bars had to be built for the car. An electric EPAS steering rack was used to retain power steering. The idea of using the Viper’s chassis was great, but the execution is incredible. The car is technically a modified mid-engine setup as the crank sits behind the front axle centerline. This helps balance the car out like no Road Runner ever was. The car is now slightly 150 pounds heavier in the rear, which is the opposite of the original issue with big-block Road Runners, which were always a bit nose-heavy lacking for traction in the rear.

Kicking the stuffing out of this Plymouth was the immediate goal, so he made the smart move and installed a roll cage. The 10-point custom chromoly cage is tucked up as tight as he can while staying safe. He also made the door bars removable to make it easy to get in and out of the car. He even fabricated an aluminum belly pan and rear diffuser to keep the car sucked to the ground.

Do you see it yet? The front wheels have been moved forward six inches from the stock position.

He originally had a twin-turbocharged Viper V-10 powerplant in the car, but ultimately decided it wasn’t for him. He blew the engine once and needed to switch over to a different fuel management system to make it perform like he wanted. Instead of spending double the money for the same or less power, he changed directions. He talked to Steve Morris Engines and they built a monster of a 426ci gen 3 Hemi with a 3.6L Kenne Bell supercharger on top. The engine made 1,115 horsepower at the crank. Backing the engine is a fully-built G-Force T56 Magnum six-speed with a twin-disc McLeod clutch and an SFI-rated bellhousing.

The 3.6L Kenne Bell blower is the icing on the Steve Morris Engines-built 426ci Gen III Hemi. Note the engine's placement...this Road Runner is front-mid engined!

The entire floor setup is made of composite materials in a bid to keep the Runner as light as possible. The rear wheel wells have been stretched two inches, and the front wheels had to be moved forward six inches. The carbon fiber hood was created using sections of the Viper hood grafted into the Road Runner shape. The rocker panels have had the pinch welds shaved and the firewall, itself a fully-custom aluminum unit, has been moved back nine inches from the stock location to accommodate the engine's new location. Inside the cabin is a full leather interior, a stereo system that will rival the Hemi's soundtrack, and Vintage Air.

Matlock isn't afraid of putting his Road Runner to the test, as he did in the burnout contest at the 2021 Holley MoParty. Those giant rear tires didn't stand a chance.

“I definitely enjoy the Hemi’s street manners and instant torque over the turbo V-10. I drive it every week, sometimes 20 miles or so, to get lunch with friends. I’m in real estate and I even show houses in it. People tell me I’m crazy to drive it like I do, but I watched my dad daily drive it my whole life. The idea of spending the time and money on a build this and not driving it is just plain stupid to me. My goal is to put more miles on it than dollars I spent on it.” – Kenny Matlock, owner.