Photos by Dave Alderman
The auto industry is unique in the way it does business. Today, cars are for the most part designed by committee. And where that’s gotten the industry? For the most part it’s put them on the brink of bankruptcy. Rewind back to the 1960s and 1970s: almost every exceptional car that came off the factory floor during that timeframe came to life by a key person in the organization, someone with the vision and the power to make things happen. Interestingly, one person also hatched the Plymouth Road Runner, but truth be known, he didn’t work for Chrysler.
It was an outsider, Brock Yates, who was responsible for this legendary piece of iron. Brock, a journalist for Car and Driver during that time, pitched his vision of the Road Runner to Chrysler’s product planner Joe Strum. Brock suggested they package a low cost, big block, no frills performance car. His vision was to stuff the 440 cubic-inch engine into a base “B” body Plymouth and retail it for under $3,000. Joe Strum was impressed with the idea and with a few changes to Brock’s original vision, the Road Runner was born and went on to become one hell raising muscle car.
When first launched in 1968, sales were considerably stronger than Plymouth anticipated and it appeared that a niche had been found. When 1969 rolled around, it was another banner year with sales up over 60 percent. By 1970 the Road Runner was imbedded into the fabric of factory muscle cars. Plymouth’s combination of great performance at an affordable price gave “lunchbox Joe” the ability to own a car that would dominate the street-racing scene.
After two years of carry-over sheetmetal, the 1970 Road Runner upped the ante on styling with a new grille, hood, front fenders, quarter panels, and rear end treatment. The new rear quarters with a non-functional scoop, and hood with a power bulge, gave the car a more aggressive look. New taillights graced the rear. Optional on the 440 and standard on the 426 Hemi was the “Air Grabber” cold air induction system. With the push of a button located on the dash, the hood would open and bring fresh air into the engine.
The base interior of the Road Runner was bare bones. A vinyl front bench seat was standard; however high back bucket seats could be ordered for added comfort. The 1970 dash was borrowed from the Charger and included a 150-mph speedo. Since the Road Runner was intended to be a spartan street racer, few luxury items were available on the option list.
The heart and soul of the Road Runner was its powertrain. The standard 383 cubic-inch V-8 developed 335 horsepower with the addition of Chrysler’s “906” heads. Next up was the 440 cubic-inch, 390-horse V-8. Topped with three Holley carburetors, the 440 Six Pack, or Six Barrel as Plymouth called it, was pure race engine. To reduce cost, Plymouth replaced the aluminum Edelbrock intake manifold early in the model year with a cast iron version but fortunately this change didn’t hamper performance. The cam for 1970 was revised with a slightly lower duration. All Six Pack engines had their rotating assembly balanced, and a forged crank helped to keep things from coming apart. Plymouth had been experiencing some bottom-end engine failures in 1968 and 1969 and with that in mind, they strengthened the connecting rods by increasing the cross-beam section. For those who wanted more power than the 440 provided, the monster 426 cubic-inch Hemi could be ordered, but buyers needed to be prepared to spend a whopping $841.05 for the privilege. Rated at 425 earth-shaking horsepower, the Hemi was the ultimate performance engine. The only change from 1969 was the replacement of solid lifters with hydraulic lifters due to customer complaints of repeated adjustment.
While sales weakened for 1970, the Road Runner gave the public what they wanted: great performance with a low price tag. Today, Road Runners are commanding high prices at the national classic car auctions. While some upper-end prices have leveled off, high quality Mopars like our 440 Six Pack with Pistol Grip cover car continue to have many more interested buyers than sellers.
Fuel For Thought
Road Runners were built in Detroit and Los Angeles
First year for Air Grabber hood
Cast iron intake replaced the aluminum intake on Six Pack cars
Hemi engine received hydraulic lifters
Chrysler paid Warner Brothers $50,000 to use the name Road Runner
Number built – 40,660 coupes
Construction – Unibody
Engine – 383 cubic-inch V-8, 440 cubic-inch V-8, 426 cubic-inch V-8
Power/Torque – 383 cubic-inch V-8, 335 horsepower, 390 lb-ft torque, 440 cubic-inch V-8, 390 horsepower, 490 lb-ft torque, 426 cubic-inch V-8, 425 horsepower, 490 lb-ft torque
Transmissions – Three-speed manual, four-speed manual, three-speed automatic
Suspension front – Unequal-length A-arms with torsion bars, anti-roll bar
Suspension rear – Live axle with semi-elliptic leaf springs
Brakes – 11-inch front and rear drums, optional front disc
Length/width/height – 202.7/81.7/56.3 inches
Wheelbase – 116 inches
Weight – 3,400 lbs.
0-60mph/quarter mile – 6.6 seconds, 14.4 seconds at 99 mph (Motor Trend, December 1969)
Top speed – 115 mph est.
MPG – 8-12 mpg est.
Price – MSRP - $ 3,284; Today – $32,300 - $59,100
Insurance cost is $358/year for a $44,100 1970 Road Runner 440 Six Pack. This is based on 3,000 miles per year of pleasure driving. *Based on a quote from Heacock Classic Car Insurance,
Engine – All Chrysler performance engines were stout. The 440 cubic-inch monster was a true factory race engine with a shot-peened and magnafluxed forged crank, special connecting rods, and a balanced rotating assembly.
Handling – The Road Runner had a respectable suspension for its time. All cars were equipped with heavy-duty front torsion bars, 0.94-inch front sway bar, heavy-duty shock absorbers, and heavy-duty rear leaf springs.
1970 Chevelle SS 454
Number built – 3,773
0-60/quarter mile – 5.4 seconds/13.81 seconds at 103.8 mph (Car and Driver, February 1970)
Top speed – 132 mph (Car and Driver, February 1970)
Price – MSRP - $3,222; Today – $30,450 - $113,490
1969 Mustang Mach 1 428 Cobra Jet
Number built – 13,261
0-60/quarter mile – 6.3 seconds, 14.5 seconds at 100 mph (Motor Trend, January 1969)
Top speed – 106 mph
Price – MSRP - $3,122; Today – $32,250 - $63,900
More performance per dollar than almost any car from 1970
Ultimate cool factor with dog dish hubcaps and bench seat
Excellent investment potential
Many unrestored cars are rusty
Difficult to find a car with the original powertrain
Restoration parts are expensive compared to other manufacturers
While the prices of Road Runners continue to go up, owners still drive them to the local car shows on a regular basis. Only very rare Road Runners are trailered to events. Mopar owners are a unique group of people who live and breathe their passion and are fanatical about their cars.
What to Pay
1970 PLYMOUTH ROAD RUNNER 440 SIX PACK
MSRP – $3,284
Low – $32,300
Average – $44,100
High – $59,100
*Based on prices from the Classic Cars and Parts Price Guide, fueled by NADA and available wherever Classic Cars and Parts magazines are sold.
Front bench seat cover $359.00
Replacement oil pan $199.00
Rebuilt power steering gear box $295.00
Quarter panel skin $265.00
Fuel tank $235.00
*Based on information from Year One Inc.,
Original Dodge and Plymouth B-Body Muscle 1966-1970 by Jim Schild
Charger, Road Runner and Super Bee Restoration Guide by Paul Herd
Dodge & Plymouth Muscle Car Red Book, 2nd Edition by Peter Sessler
Big-Block Mopar Engines by Don Taylor
Overall – The 1970 Road Runner proved to be a strong player in the factory muscle car wars. With a low price and high horsepower, it optimized the best of the decade with pure and unadulterated performance. The Road Runner reflects an era that unfortunately will probably never be seen again.