There is no doubt that the Plymouth Road Runner was one of the most revered names during the muscle car era. While some of the early Road Runner models take in a lot of money, Plymouth tried to keep the nameplate going well after the muscle car had come to an end.
In 1972, Plymouth saw a huge decline in sales for its beloved budget muscle car. Tougher emission regulations killed of the 426 HEMI and only 5 units of the famed 440+6 were built before emissions did that engine in as well. Gasoline costs and higher insurance for muscle cars, all put a damper on the once-boulevard racer. So Plymouth went back to the drawing boards and designed completely new sheet metal for the 1973 model year.
The 1973 cars featured more conventional squared-up front-end styling that changes that resembled more of the four-door offerings in the Plymouth lineup than the car it replaced. The redesign helped boost sales 40% over the 1972 model, despite the Road Runner having a lackluster 5.2-liter (318 cubic-inch) V8 as its now standard powerplant. When equipped with dual exhaust the 318 delivered 170 horsepower.
Other engines ranged from a 5.6-liter (340 cubic-inch) four-barrel small-block V8 to 6.6-liter (400 cubic-inch) and 7.2-liter (440 cubic-inch) big-block V8s. Although the 440 remained, it now only produced 285 emissions-choked horsepower.
Needless, the 1973 Plymouth Road Runner has never become a highly-regarded muscle car in its outright. But it hasn’t stopped a few diehard Mopar fans from building their own unique take on the boxier B-Body bird.
Vanguard Motor Sales, located in Plymouth, Michigan is known for selling some of the finest muscle car examples on the planet. To our surprise, they recently added a very unique 1973 Plymouth Road Runner that has undergone the knife to become a beautiful supercharged machine.
Built as a Pro Street car, the Road Runner has undergone an extensive rotisserie build. Painted in a two-stage Sublime green, the tubbed-out Road Runner is definitely an eye-catcher.
Besides the color, one of the first things you see that pops out at you is the massive Enderle-style scoop atop an Indy 8-71 blower on a 7.3-liter (446 cubic-inch) V8 poking through the hood. Built by Total Engine of Bloomington, Minnesota, the engine is balanced and blueprinted.
Other performance highlights include an Indy 440-1 Max Wedge Aluminum Head and Manifold Combo, JE Forged Pistons, Manley Rods, an Eagle Forged Crank, Comp Cams Flat-Tappet Blower Cam, ATI Damper and Gear Drive, Milodon Oil Pan, Windage Tray, Ceramic Coated TTI Exhaust Headers, and an MSD Ignition System. The cooling system has been upgraded with an Electric Water Pump, Dual Electric Cooling Fans, and a BeCool Aluminum Radiator.
Power is sent through an A727 Torqueflite 3-Speed Automatic Transmission that was built by Pro Trans in California, incorporating All-Aluminum Internals, a Turbo-Action Hughes HD 3,000 Stall Converter, Manual Valve Body, and a Remote Cooler.
The car also features a Mark Williams narrowed 8 3/4-inch rear end (489 case) with chromoly drive and axle shafts, Richmond 3.91:1 gears, and Sure-Grip differential in a reinforced housing sends power to the massive rear tires. Of course, there is updated stopping power with four-wheel disc brakes with four-piston calipers and slotted rotors.
Underneath, the color includes a reinforced torque boxes, front and rear driveshaft loops, torsion bar front suspension, leaf spring rear suspension, rear traction bars, and a 3-inch dual exhaust system with electric cutouts and Flowmaster exhaust.
Inside, the features a custom Black and Grey-colored interior, with front bucket seat with lap belts, custom front and rear panelings, customized center console with a B&M shifter, AutoMeter gauges, power windows, and a custom upholstered trunk.
The car has been a feature car at the “Mopar at the Mansion” show at the Playboy Mansion, as well as, the Mopar Collector’s Guide cover car.
But with all those power and looks, it isn’t cheap. Vanguard has the car listed at $149,900. But with cars like a 2018 Dodge Challenger SRT Demon going for even more, this Road Runner is sure to get more looks whereever it goes.
1973 Plymouth Road Runner Pro Street Image Gallery: