In 1968, Plymouth decided that muscle cars had gotten too far from their original purpose: cheap and very fast thrills. The company paid $50,000 to Warner Brothers to affix a certain cartoon bird onto its new vehicle, which was based on a stripped Belvedere pillared coupe body, and the Road Runner was born. The standard engine was MOPAR's tried and true 383 cid power plant, which was treated to the heads, manifolds, camshafts, valve springs, and crankcase windage tray from the race ready 440 Magnum. The result: 335 bhp and 425lb-ft. This was coupled with numerous other performance features including beefed up suspensions, manual transmissions, brakes, tires. The interior was basic: a no nonsense bench seat and no carpeting - just rubber floor mats. The main attraction was a base price of $2896. For those who wanted a little bit extra, there was one engine option; for $714 Plymouth would slide in a 426 Hemi, ultimate street engine, unmatched by any other except the Viper-10, the “426 Hemi”. With 425 horsepower, that pretty much guaranteed the win at streetlight races. Although the Hemi clashed with the budget based principle of the Road Runner, 1/4 mile times in the low 13s needed no apologies. A hardtop coupe and functional hood vents were added mid year during 1968. A horn that went "beep-beep" complimented the road runner decals (in gray due to time constraints) that were standard on all Road Runners. Plymouth originally estimated that it would sell 2,500 vehicles in 1968; it actually sold 45,000. The 1968 Road Runner is perhaps the second most significant muscle car to the 1964 Pontiac GTO as it shifted the market back to its bang for the buck roots.
2D Pillared Coupe: 29,240
2D Hardtop Coupe: 15,359
383 V8 335 bhp @ 5200 rpm, 425 lb-ft @ 3400 rpm.
426 Hemi V8 425 bhp @ 5000 rpm, 490 lb-ft @ 4000 rpm.
383/335: 0-60 in 7.1 sec, 1/4 mile in 15.0 sec @ 96mph.
426/425: 0-60 in 5.3 sec, 1/4 mile in 13.55 sec @ 105mph.
The Roadrunner aimed squarely at the younger buyers interested in high performance but couldn’t afford a GTX or thought it too fancy. It was lighter than the smaller 'Cuda to make it both light and cheap it had few amenities, creature comforts gave way to sheer performance and cost considerations.
The Roadrunner was one tough bird. Unlike some sports cars it was built for serious street work which might explain why so many have survived to today. The Roadrunner was allegedly a favorite of moonshiners, faster than almost any police car and tough enough to take practically any bump and having good ground clearance as well.
Yes, the Road Runner was based on the cartoon, and came complete with a horn that went beep beep! and an ad campaign featuring Wiley Coyote. Depending on the model and year, the steering wheel had a little Road Runner, and the air cleaner had a cartoon with the logo "Coyote Duster."
In 1968 the stock base engine was a 383 CID, with heads, intake, cam, and exhaust manifolds from the 440 Super Commando making it the fastest 383 ever with 335 (gross) horsepower. A four-speed manual was standard (three speed transmissions were the most common in those days).
In 1969, Ford responded with the Cobra (a Fairlane with a 428), but the Road Runner kept going to win Motor Trend's Car of the Year award; the 440 6-barrel really helped, providing acceleration nearly equal to the Hemi at least up to highway speeds and with a much lower price tag.
The 440 cubic inch, triple-carburetor (two barrels each) Road Runner took the concept to its natural conclusion, even eliminating hubcaps. The Super Bee, on the other hand, added the Ramcharger air scoop on the hood; unlike many scoops, this one was functional and standard with the deep-gulping Hemi. On the Dodge, the three 2-barrel carb setup was named the Six Pack, and it put out 390 hp (gross). Keep in mind as you read this that horsepower meant more in those days when it came at lower rpms. Wheels were moderately large for the time, 15 x 6; air conditioning and cruise were not part of the package.