Easy Out
July 10, 2024
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THE AUTO BUILDER
Featured
TPI: TODAY’S PERFORMANCE INCREASE
There are few modifications that can be made to an engine that can give both increased performance and better fuel economy. In these days of increased gasoline prices (nearly $4.50 per gallon), fuel mileage is an important consideration for vintage trucks that owners consider their daily drivers. For many reasons, vintage pickups are becoming not just weekend toys but also weekday workers. And one of the best ways to increase both performance and mileage is with an electronic fuel-injection system.
From Vegas with Horsepower
Las Vegas, Nevada, baby! Picture this: the Holley LS Fest West roaring into town like a beast on four wheels, revving up the asphalt at the Las Vegas Motor Speedway from April 26-28, 2024. This shindig ain’t your average car meet; nah, it’s a full-throttle celebration of all things LS engine from GM. You got your gearheads from every corner gathering round, ready to rip it up in Autocross, Drifting, Drag Racing, Off-Road showdowns, and then some. But it’s not just about the racing; it’s about the vibe, man. Folks bonding over their love for LS-powered rides, swapping stories, and soaking in that sweet, sweet automotive culture.
Square Peg In A Round Hole
When the engineers at Chevrolet designed the fuel inlet and fuel cap for the early Nova, they must not have looked at the rest of the car. Novas aren’t called shoeboxes for no reason; with the exception of the wheels–and that gas cap–they are basically square. Wheels have to be round, but the gas cap, well….
Spotlighter
RAPID TRANSIT SYSTEM
A Member In Good Standing—A ’70 Plymouth GTX 440 Six-Barrel
Considered a “gentleman’s muscle car,” the upscale Plymouth GTX two-door hardtop was restyled in 1970, offering cleaner side body panels along with revised front and rear fascias. The grille had a unique telephone-receiver look to it, the taillight treatment was changed, and the car was no longer available as a convertible.
Author
Jim Maxwell
Words & Photography
The Upscale Muscle Car: 1970 Plymouth GTX
Considered a “gentleman’s muscle car,” the upscale Plymouth GTX two-door hardtop was restyled in 1970, offering cleaner side body panels along with revised front and rear fascias. The grille had a unique telephone-receiver look to it, the taillight treatment was changed, and the car was no longer available as a convertible.
Plymouth’s Rapid Transit System
The GTX was a member of Plymouth’s Rapid Transit System performance car marketing program, and to add the visual excitement those times demanded, these cars were available with high-impact paint colors, including In Violet (purple), Limelight (green), Vitamin C (orange), Tor-red, Lemon Twist (yellow), and Moulin Rouge (pink).
Supercar Clinics and Promotion
Special Supercar clinics were conducted at Chrysler-Plymouth dealerships across America by Sox & Martin and Don Grotheer for Plymouth to promote the GTX and other Rapid Transit vehicles, such as the Road Runner, the Duster 340, the Sport Fury GT, the ’Cuda, and the SuperBird.
Standard Features and Engine Options
The GTX was known as the RS23 model within the dealership showrooms, and it came standard with extra-heavy-duty shocks and suspension, driveshaft and U-joints, rear axle, 6-inch-wide wheels, battery and brakes, as well as bucket seats and a Power Bulge hood.
There were only three engines available: the standard Super Commando 375hp, 440cid V-8; the optional 390hp, 440cid six-barrel V-8; and of course the optional 425hp, 426cid Street Hemi. Transmission choices were either a high-upshift, competition-type Torqueflite automatic or a heavy-duty four-speed manual transmission. The rear-axle ratio is 3.55:1.
The Appeal of the GTX in 1970
“No Brag, Just Fact” was how the GTX was presented in the factory brochures, and there was little question that if you could afford one, owning a GTX was a way to show that you appreciated great performance wrapped in the finer things of life. With a base price of $3,535, the GTX was some $600 more than the lesser-equipped Road Runner, which was no doubt why the stripped Road Runners sold in much higher numbers. More than 40,000 Road Runners were produced in 1970, while fewer than 8,000 GTX examples were produced.
A Factory FC7 Car with Desirable Options
This particular GTX is a factory FC7 car, which, translated, means it was painted In Violet metallic from the factory. Other desirable options included the E87 6V 440+6 three two-barrel engine with the vacuum-operated N96 functional Air Grabber hood scoop. This car also has white side stripes and a black hood stripe—both factory options—along with a center console. An automatic was the chosen transmission, with the optional 15-inch wheels with F60-15 Goodyear Polyglas rubber. Other options included power disc brakes, power steering, and AM radio. The car was sold new at the Andis Motors dealership in Greenfield, Indiana, with a retail price of $4,193.70.
Current Ownership and Restoration
Today, this Plymouth is owned by Mopar collector Bill Sefton, who enjoys the car immensely, as he takes it on cruises in and around his native home in Scottsdale, Arizona. The beautiful restoration took place in New York by the previous owner, Ron Sannini. He deciphered the original option codes, as the car had the original broadcast sheet, which documents the factory equipment along with the fender tag. These information sheets typically were inserted in the seat springs under the rear seat. Not all cars came with broadcast sheets, which are also referred to as build sheets, and some came with the wrong build sheet for the car. When you find a vintage Mopar with this paperwork, it adds value to the car and is an excellent way to verify options and to ensure that the car is properly restored.
The Rarity and Desirability of the 1970 GTX
A fully documented Mopar muscle car is a highly desirable machine to own these days, especially one that was painted with a high-impact color. This car is rare, as only 328 ’70 GTX models came through with the 440 six-barrel engine and Torqueflite transmission. While this example is super-detailed and in top museum condition, Sefton isn’t afraid to take it out on the open road and let it loose so those three Holley carburetors will open up all the way—just as one would expect from a Rapid Transit vehicle.
This classic Mopar resides in sun-baked Scottsdale, Arizona, so the notation that it was weatherproofed to 30 below zero when new seems moot, but it adds a great detail to the car’s restoration.
This is a “1 of 328” car, as factory equipped with the 440-6 engine. Plymouth called its version of this potent mill the 440 Six-Barrel and 440+6, while Dodge called it the 440 Six-Pack. Either way, it was rated at 390 hp at 4,700 rpm. High-performance Mopar engines of this era came painted orange
Three 2300-series two-barrel Holley carburetors made up the intake on the 440 Mopar six-barrel cars, and they delivered 1,200 cfm total air capacity.
A 70-amp battery was ordered, and note the orange engine paint that extends on the positive battery cable. This wasn’t a sloppy oversight during the restoration—it was done to duplicate the manner in which these cars were production built when new. This is highly documented as correct, with verification from original non-restored photographs.
With the scoop opened, there’s an Air Grabber character baring its teeth, and if that didn’t get your attention, the sound of the engine certainly would!
The biggest deal on this fender tag is the E87 marking, which means 440 Six-Barrel. Chrysler cars were unique, as they were equipped with these tags that told the story of the way the car was built at the factory.
The GTX package came with bucket seats and a Rally instrument panel, while a center console was optional at a price of $54.45. This car came with a black interior and AM radio, which cost $61.55
The GTX model was an upscale muscle car, with upholstery that was a notch above the standard Belvedere trim. On the outside, the GTX looked like a Road Runner from a distance, but extra chrome here and there, plus the premium interior trim, was the difference.
The manufacturer’s suggested retail price on this B-body Plymouth was $4,193.70, and this car could be considered a no-nonsense vehicle with few options. Performance was key here, with the addition of the six-barrel 440.
Under the rear seat there is usually a broadcast sheet. However, some cars didn’t have them, and some cars were mistakenly supplied with sheets belonging to other cars. This car was equipped with the correct paperwork, and that’s always helpful when researching and documenting a restoration.
V6W was factory code for the side sport stripes in white. This could also be deleted from the factory, and depending on the base color, the stripes were available in white, black and gold.
F60x15 Polyglas GT Goodyears were mounted on 15x7-inch Rallye Road wheels. These steel wheels were a $43 option. They added not only an inch-wider wheel but also a stylish touch to the car.
Even though Rallye Road wheels were optioned, the spare tire had a standard black-painted wheel, which was Chrysler production protocol.
The original markings were still on the car; the F60 refers to the set of five U84 raised-white-letter tires. Original markings were also inside the decklid, as well as in the doorjamb.
