The Plymouth Road Runner was manufactured between 1968 and 1980 by the Chrysler’s Plymouth division. In 1968, many thought that original muscle cars were slipping away from their image as very inexpensive, fast automobiles as they increased options. Although Plymouth already had the GTX, designers wanted to reinvent the muscle car concept. Plymouth desired an automobile capable of 14-second-quarter mile speeds and selling for less than $ 3000. Both goals were accomplished, and the low-cost muscle automobile hit the road. The Road Runner’s success would much outstrip that of the upscale and lower volume GTX, with which it was frequently mistaken.
Plymouth set out to produce a back-to-basics muscle car, paying Warner Brothers $50,000 to utilize the name and likeness of their Road Runner cartoon character, and employing the Chrysler B platform. Everything necessary for performance and handling has been beefed up and improved; everything superfluous has been omitted. The interior was sparse, with a basic cloth-and-vinyl bench seat, early versions without even carpeting, and limited options – only power steering and front disc brakes, AM radio, air conditioning, and automatic transmission were offered. A floor-mounted shifter was equipped with merely a rubber boot and no console, allowing for the usage of a bench seat. The initial 1968 vehicles were only available as two-door pillared coupes, but later in the model year, a two-door “hardtop” type was introduced. The Road Runner was based on the Belvedere from 1968 to 1970, while the GTX was based on the Satellite, a car with a higher degree of trim and subtle variations in the grilles and taillights.
In 1970, Plymouth dealers distributed this advertising windbreaker. Plymouth used the “heart with an arrowhead at the bottom” motif in its advertising campaign that year. The Road Runner is wearing a helmet emblazoned with the same symbol.
The standard Internal combustion engine was a 383 cubic inch Road Runner V8 producing 335 horsepower and 425 pound-feet of torque. Plymouth will install a 426 CID Hemi engine with 425 bhp and 490 lb.-ft of torque for an additional $724. Due to its lightweight, the 6-passenger Road Runner could cover the quarter-mile in 13.5 seconds at a top speed of 105 mph. It was one of the best engines of the muscle car period, and the Road Runner would prove to be one of the best platforms for it.
A four-speed manual transmission with floor shifter was standard equipment, while a three-speed TorqueFlite automatic transmission was available. The early four-speed ’68 Road Runners utilized Inland shifters, which were replaced by the more precise Hurst shifters.
Plymouth anticipated selling approximately 2,000 vehicles in 1968; actual sales totaled approximately 45,000. This placed the Road Runner third in muscle car sales, behind only the Pontiac GTO and Chevrolet’s SS-396 Chevelle. Dodge introduced the Super Bee, the Road Runner’s cousin, in mid-1968 in response to Plymouth’s success and dealer demand for their own low-priced muscle car after the Dodge Boys began the model year with the more expensive Charger R/T and Coronet R/T – both of which were priced similarly to or higher than the Plymouth GTX.
The 1969 model retained the fundamental design but had minor aesthetic alterations. Six of the Hemi convertibles were equipped with automatic gearboxes, while the remaining four were equipped with four-speed manual transmissions. There are three that are known to exist. This year, Ford added the “Air Grabber” option; it consisted of an air duct assembly mounted to the underside of the hood and connected to twin rectangular upward-facing scoops in the hood. When the hood was closed, a rubber seal covered an unsilenced large-oval air cleaner assembly that ducted air directly into the engine. The hood scoops may be opened and closed using a lever located behind the dashboard. Additionally, a convertible was added.
While the 383 ci engine remained the standard, a 440 ci engine equipped with three two-barrel carburetors, dubbed the 440 6bbl, was added to the lineup in the middle of the year to qualify the engine for the Super Stock drag racing class. Dodge advertised their three two-barrel configurations as the 440 Six Pack on Super Bee vehicles, and this well-known nomenclature is frequently confused with Plymouths. 440 6bbl Road Runners lacked wheel coverings and hubcaps, featured flat black H wheels, and a lift-off fiberglass hood with an operable hood scoop in original black. The fifth character in the VIN of this model of Road Runner and Super Bee was a Code M, and it was also referred to as the A12 model. At 3200 rpm, its 440 engine produced 390 horsepower and 490 lb.-ft of torque, very similar to Hemi’s statistics but at a lower engine speed. This meant that the less expensive 440 6bbl was nearly as quick as the 426 Hemi at highway speeds. Along with the economical yet powerful 383 and the insanely fast Hemi, this choice helped drive Plymouth and corporate brother Dodge to the top of the dragstrip elite.
The 1969 Motor Trend Car of the Year was the Road Runner. Sales nearly doubled to 82,109 units, placing it second behind the Chevelle SS-396 and over 10,000 units ahead of the Pontiac GTO, which fell to third place in this market sector.
1970 saw the addition of fresh front and rear-end styling to the original 1968 design, which proved to be another hit. Updates featured a new grille, leather seats, hood, front fenders, quarter panels, single-piston Kelsey-Hayes disc brakes, and even non-functional scoops in the rear quarters. This year, the Air Grabber option’s design and functioning were enhanced to promote both efficiency and the “intimidation factor.” A switch beneath the dash activated a vacuum servo, gradually raising the forward-facing scoop and revealing shark-like teeth on both sides. For that year, “High Impact” colors such as In-Violet, Moulin Rouge, and Vitamin C were offered. The 1970 Road Runner and GTX remained appealing and popular vehicles. The engine line-up remained intact, but a heavy-duty three-speed manual transmission became the standard transmission, relegating the four-speed and TorqueFlite automatic to the options list. This was to be the Road Runner convertible’s second and final year, with only 834 units produced. These cars are more expensive than the 1969 version because of the improved dash, high-impact colors, and additional choices, like the new high-back bucket seats, shared with other Chrysler models and including built-in headrests.
For 1970, the 440 Six Barrel was reduced to option status. The 1969 “M” Code Edelbrock aluminum intake was replaced with a factory-produced cast iron piece; however, early in the iron intake-equipped 440+6 run, there was a recall, and they were supposed to be replaced with the more desirable Edelbrock intake from the previous year.
The 1970 Road Runner’s sales fell more than 50% year over year to roughly 41,000 units. This would also be the final year of production for the roadrunner convertible, which produced 834 units. Only three road runner convertibles with the Hemi designation were manufactured. The decline in sales of the Road Runner and other muscle cars was caused by insurance companies imposing surcharges on muscle car policies, effectively making insurance premiums for high-performance vehicles prohibitively expensive. Additionally, Plymouth produced another bargain-basement muscle vehicle in 1970, the tiny Duster 340, which was powered by a 275-horsepower 340 Magnum V8 that performed as good as, if not better than, a 383 Road Runner in the lighter-weight compact A-body. Additionally, the Duster 340 was priced lower than the Road Runner and qualified for significantly lower insurance rates due to its smaller engine.