Classic Car Buyer's Guide: 1968-1970 Plymouth Roadrunner
By Patrick Smith
The car that started low buck muscle, Plymouth's Roadrunner beep beeped its way into America's heart in 1968 and stormed across drag strips and into owner's garages. The runaway sales hit sparked a slew of imitators. It was one of the last models to appear before the market was totally saturated. It is a revered icon today and collectors still pursue the Roadrunner with the same passion as Wile E Coyote. Over priced during the speculator driven market of 2007-2009, Roadrunners have settled to reasonable, even tempting prices. Read on to learn how to capture a fast bird of your own.
Year by Year Styling: Roadrunners debuted in 1968 as a special variant of the Plymouth Satellite. A coupe and hardtop body was offered. The 1968 body was Plymouth's version of the new Coke bottle styling that appeared on 1968 GM A- bodies. The 1968 grille is a simple square cut out pattern with twin headlamps and blacked out trim. The tail lamps were simple square units with radiused corners. They used round side markers lamps. All Roadrunners got a special twin scooped hood with narrow toaster slotted grilles and engine call outs on the sides. The 1969 Roadrunner was very similar in appearance except the grille had four long rectangular bars between the headlamps. The side marker lamps were rectangular this year. For 1970, the grille, fenders and rear deck were completely different. The grille was a simple loop with vertical finned inserts which were blacked out. A vent rests between the grill and bumper. The tail lamps are larger, separate cast metal housings with horizontal lenses. The deck lid is concave and has Plymouth lettering on it. The Roadrunner hood for 1970 was completely new with a slightly raised dome in the center with '383', '426'or '440' callouts on a metal plate attached to the end of the dome facing the windshield. The optional air induction system was also completely different to the 1968-69 versions which will be covered in the options section.
1968 Roadrunner has round sidemarker lens and plain square stamped grille.
1969 Roadrunner used plastic grille divided into four rectangles and square sidemarker lenses.
1970 model had looped barbell style grille with vertical fins.
Drivetrains: Roadrunners came two ways, fast and faster. In 1968, the standard engine was a 383 four barrel 'Roadrunner' engine which was the same as the 383 Magnum and Commando in other Mopar car lines. You got a four speed manual floor shift transmission as standard equipment that year. The heavy duty 727 Torqueflite automatic was optional and available in either column or optional console shift. The only engine option was a 426 hemi with dual quad Carter AFB carbs and solid camshaft. Transmission could be either four speed or 727 automatic. In 1969, a mid range engine option filled the space between 383 and hemi halfway through the calendar year called 440-six pack. It was essentially the Dodge Superbee engine package with three Holley two barrels on an Edelbrock aluminum intake. The 1969 440 Six Pack Roadrunners are very scarce and many clones have been made. It was a package car and not a simple big engine hop up. For 1970, Plymouth reissued the 440 Six Pack Roadrunner. The 426 hemi returned with a hydraulic camshaft and a greatly improved manual shift linkage to compliment the excellent 883 New Departure four speed transmission. The 383 engine held the fort as the standard engine. New for 1970 was a change in transmission specs, Plymouth offered the three speed manual transmission as standard equipment in order to lower the price of the car. Four speeds were optional for 1970.
383 Commando four barrel was Roadrunner's standard engine.
The 440 Six Pack is rare but not as expensive as the hemi.
Desirable Options: Since the Roadrunner started out as a package car, options weren't pushed too heavily in the beginning. Once it became clear it was a sales success, marketers added items to the mix. In 1968, the rare Roadrunner was the hardtop, most were coupes. In 1969, that figure reversed as the hardtop gained foothold. Most 1968 Roadrunners had very little in the way of creature comforts. Vinyl floor mats and taxi cab upholstery was the norm. The convertible body style must rate as the rarest however. Back in the day, convertibles didn't appeal to guys interested in power as it was heavier than a coupe. The options that mattered to original buyers were engine and performance related. The cold air RamCharger hood is a favorite and often added by restorers. The four speed shifter and Sure Grip limited slip differential. Woodgrain steering wheels, console, bucket seats, AM/FM radio and tinted glass are all desirable but considered frills by original buyers. It's common today to find these added on by restorers.
Ramcharger Induction hood is very desirable and motorized with pop up door in 1970.
Pistol Grip shifter, clock and radio are popular options.
Certain performance options such as power disc brakes, power steering are scarce on Roadrunners as this drove the price up. Air conditioning although available with the 383 engine, was so expensive you rarely see it. Imagine paying almost ten percent of the price of a new car for one option. 1970 was the first year you could find a nicely equipped Roadrunner but you'll pay a premium for it.
In terms of desirability, the engines to get are 426 hemi, 440 six pack and 383 in that order. The four speed transmission holds a significant edge in value as well, being a performance model. The best non performance options to get are appearance items such as High Impact paint, optional stripes, wheel well trim, and rallye wheels. The right color and trim really sets off this car and makes it very desirable. High Impact paint colors were extra cost and included shades like Bahama Yellow, Rally Red, Plum Crazy Purple, Panther Pink and Sassy Grass Green. The Day Glo colored cars tend to command a higher price than normal colors. Roadrunners are popular with styled steel wheels, rallye wheels or dog dish hubcaps with body color rims.
This 1969 hemi four speed in Hemi Orange is also the low production coupe bodystyle.
High Impact paint colors are desirable such as this Burnt Orange Metallic with Burnt Orange vinyl interior1970 Roadrunner.
Things to Look Out For: Mopar muscle cars have been very popular for a long time. They've experienced two major price swings through the 1980s and more recently, the 2006-2008 era. This means many have been restored a couple of times now. It also means you have to be wary of buying a clone that may be marketed as genuine. First, we'll cover the Roadrunner's inherent problem areas then proceed towards spotting a clone in the verification section. Roadrunners are unit body cars, meaning they have no separate chassis. A perimeter frame is used with extensive spot welding and a separate K frame holding the engine in place. A set of torsion bars installed in a transmission cross member handles the drive train placement duties. Out back, leaf springs and live rear axle takes care of the rear suspension duties.
Rust is the mortal enemy of any unibody car. On Roadrunners, rust tends to attack the last three feet of the rear frame rails as well as the leaf spring perches. The front floor pans are known to rust at the toe boards from pooled moisture. The hood hinges and surrounding sheet metal often rust away, leaving a difficult to open hood with alignment problems to deal with. The lower door skins often get pinholes and are swathed in bondo instead of replacing the metal on old unrestored cars. The inner fender panels underneath the hood can rust out as well and on bad examples, you'll be replacing the shock towers as well. Since torsion bars enter the transmission cross member, you'll need to check it for rust as well. Roadrunners were often drag raced so it's possible you'll encounter a car with altered rear quarter panels for big tire and wheel combinations. With a drag racing past and naturally rusted metal, it's common to find rusty or replaced quarters on a car.
The good news is all the important sheet metal and frame sections have been reproduced. A car that needs replacements of a few items is only a big deal if you have to pay someone to repair it. A rusted out hulk isn't worth trying to restore unless it's very rare and numbers matching. A hemi or Six Pack car is worth replacing all the floor pans, rear quarters and front end sheet metal on. A base 383 coupe is more likely to be a parts donor or casual build up for street use instead of a restoration trailer queen.
The engines and transmissions are very stout on these cars. Rebuilds are going to be from high mileage wear or done as "insurance" against damage with long term storage vehicles. The 727 automatic is very tough. Even badly worn examples work well enough to move a car around. It's common to find them highly modified internally with shift kits or even full manual pattern valve bodies, simulating a manual transmission. This highlights the drag race nature of the car when new and many owners still take them to the local track. The only weak spot to watch for on 727s is the rear sprag clutch on the tail shaft which can fail under hard use.
You should decide early what kind of Roadrunner you want before shopping. Do you want a show winner stock car, a street strip vehicle with some mods or a casual street machine? They act differently and price ranges from affordable to expensive. Don't make the error of buying a well built street/strip car, thinking you can tame it for the street by replacing the hot rod parts with stock items. This rarely works because drivetrains are modified as complete systems. If you change the carburetion, the exhaust, intake and ignition has to change to match. A notable camshaft change usually alters everything else on the car as well. You'd be farther ahead to select a stock or mild street machine than try to make a marginal track only car livable on the street. I mention this because Mopars often participate at racing events. You'll be seeing a few of them for sale.
Modified unibodies with cage systems, four link rear suspensions and special frame connectors are usually found on race cars and these are considered irreversible changes. The classic car insurance brokers tend to classify such cars in the modified category with slightly higher premiums than stock vehicles.
Documentation and Authentication: Here we'll be dealing with spotting clones and alterations affecting value of the car. Since the Satellite shell is the base of a Roadrunner, you'll often find a reproduction for sale. The first place to look is the VIN number. A Roadrunner VIN starts with RM. Roadrunners have two basic configurations; the 383 base engine and the 440 Six Pack or 426 hemi upgrades. The fifth digit tells you the engine size. From 1968-69 the 383 four barrel used the letter 'H'. A 426 hemi used the letter 'J". New for 1969 was the 440 Six Pack which used the letter 'M'. In 1970, those codes changed to "N" for 383 Magnum, 'R' for 426 hemi and 'V' for 440 Six Pack. These are the only engines used on Roadrunners those years. Hemi and Six Pack Roadrunners share lots of details and special identifying marks useful for determining whether your vehicle is genuine or a cloned muscle car. A hemi or Six Pack Roadrunner wasn't just an engine swap deal. They shared a 26-inch radiator opening in the cradle which other Roadrunners did not get. The torsion bar rods are thicker, the rear leaf springs are different and the K frame has a welded skid plate beneath the oil pan to protect it from caving in during violent bottoming out on drives. One thing all Roadrunners shared however, are welded rear leaf spring torque boxes surrounding the front spring perches. Other special identification includes 3/8 diameter fuel lines for the hemi while the Six Pack used 5/8 diameter fuel lines. These lines are metal and go right to the gas tank. A backyard clone often skips these details and will have the smaller diameter lines intact.
The K frame with big torsion bars and welded skid plate is used on Six Pack and hemi cars.
Fully boxed leaf spring perches indicate Roadrunner bodystyle, but check elsewhere as clones will have these welded in too.
Cloning has been a problem for a long time as there are many which have been produced for personal enjoyment and have since moved into the car market place. An unscrupulous or uninformed seller may sell it as a genuine Roadrunner. Sadly, many of the formerly foolproof items of verification have been reproduced now. Indeed, it's possible to make a very good clone. Don't let a fresh paint job with lots of popular options sway you. Sometimes a clean, minimal optioned car winds up being the smart choice. These cars were stripper models until 1970. Let's examine more in depth ways to identify a Roadrunner by partial VIN numbers.
An unmolested car with minimal options is valued over a tarted up car missing its original drive line.
Hidden partial VIN numbers were used by law enforcement to track stolen vehicles. They're useful for verifying a car's identity. The rad cradle is stamped with a partial VIN which includes the engine code. Reproduction rad cradles are blank in that area unless stamped by someone after purchase. Partial VINs are also found stamped in the metal lip under the trunk weather strip rubber. You can use these last six digits to match up the engine and transmissions as well. The engine partial VIN is found on the left rear cylinder head near the bell housing flange. The automatic transmission partial VIN stamped above the oil pan rail on the passenger side. Manual transmissions have a machined pad on the passenger side of main case which identifies the model and gear set used. A partial VIN will also be on the case but not necessarily on the same side. Check both sides of the case. The engine partial VIN is stamped on a machined pad above the oil pan rail on the passenger side just rear of the engine mount. You will also find extra engine related codes on a machined pad besides the distributor. Consult a service manual for decoding the letters. This will help you find a fast flyer without having your wings clipped.
Check for partial VIN under the trunk weatherstrip rubber.