1967 Plymouth Belvedere GTX: The 440 Super Commando Gets a Suit

Car and Driver tested the first GTX before Plymouth had even published its price. The November 1966 report estimated about $3,900 for a hardtop with the 440, TorqueFlite, a 3.23 axle and front disc brakes, and then measured it: 60 mph in 6.0 seconds, the quarter-mile in 14.4 seconds at 98 mph, and 118 mph observed. The brakes told a less flattering story. The first stop from 80 mph took 318 feet, the discs then faded, and the magazine could not complete a practical 80-to-0 series. That mix of speed and unfinished business is a fair summary of Plymouth's new car.¹

The GTX was Plymouth's answer to the cars already selling the idea. Over-Drive's fact sheet describes it as designed and marketed as a pure performance model, built to compete with General Motors and Ford muscle cars, and Ate Up With Motor's Road Runner history calls it Plymouth's own GTO rival, new for 1967. It was not a stripped car. Plymouth built it as a Belvedere-based two-door hardtop, body RS23, and convertible, RS27, in series CR2-P, trimmed to the level of the luxury Satellite and then given the big 440 as its standard engine.^2,3

The standard-equipment list reads like a promise that performance did not have to mean austerity. Over-Drive lists everything a Satellite carried, then front bucket seats with a console or a center armrest seat, a chrome Pit Stop gas cap, Red Streak 7.75x14 tires, dual hood scoops, dual sport stripes, stainless lower body trim and heavy-duty brakes, suspension and battery. The fact sheet also describes a blacked-out grille and special rear trim. The GTX came dressed; the scoops on its hood were simulated, and the power underneath them was not.²

The power was the 440 Super Commando, rated 375 horsepower at 4,600 rpm and 480 lb-ft at 3,200, SAE gross. Over-Drive describes a hotter camshaft, with 268 degrees of intake and 284 degrees of exhaust duration and 0.450 and 0.465 inches of lift, a larger four-barrel carburetor, bigger valves, lower-restriction exhaust manifolds, dual exhausts and a dual-snorkel air cleaner. The carburetor was a Carter AFB four-barrel. The only optional engine was the 426 Street Hemi, rated 425 horsepower and 490 lb-ft, which Over-Drive lists at $564. There was no smaller engine: every GTX had either the 440 or the Hemi.^2,4,1

The drivetrain was built around the choice of gearbox. The heavy-duty TorqueFlite automatic was the standard transmission, and a four-speed manual was the alternative. Car Life reported that the two were not simply interchangeable: four-speed cars received a 9.75-inch ring gear, against 8.75 inches with the TorqueFlite, plus firmer torsion bars and six-leaf rear springs. The car rode Plymouth's 116-inch intermediate wheelbase at an overall length of 200.5 inches, and the production table gives shipping weights of 3,535 pounds for the hardtop and 3,615 pounds for the convertible, factory figures rather than scale readings.^2,4

The price put the GTX well above the car it was built from. The production table lists the GTX hardtop at $3,178 and the convertible at $3,418, against $2,747 and $2,986 for the Satellite hardtop and convertible, a difference of $431 on the hardtop. Car Life's test hardtop listed at exactly $3,178 FOB and cost $3,649 as tested, with a limited-slip 3.23 axle and power disc brakes. Car and Driver's pre-release figure of about $3,900 was an estimate for its own equipped car, not a list price. For the $431, the GTX buyer got the 440 without having to order it, along with the heavy-duty running gear.^2,4,1

Car Life's test explains why two magazines could report different GTXs honestly. Its hardtop weighed 4,240 pounds as tested, 231 pounds more than Car and Driver's 4,009, and it reached 60 mph in 6.6 seconds and ran the quarter-mile in 15.2 seconds at 97 mph. It reached a top speed of 120 mph at 5,000 rpm. Both cars had the 440 and TorqueFlite with a 3.23 axle; the weight, the equipment and the test conditions differed. Each set of numbers belongs to its own car, and neither is the GTX's number. Together they show how far equipment and test weight could move a result.^4,1

The production count comes with its own warning label. Over-Drive's table lists 12,010 GTX hardtops and 680 convertibles, 12,690 in all, but notes that the GTX figures were estimated from dealer sales and should be treated as close rather than exact; the fact-sheet text rounds them to about 12,000 hardtops delivered and about 680 convertibles built. The same note says most records fold the GTX into the Satellite totals, which the table gives as 18,318 hardtops and 1,370 convertibles. On the table's figures, convertibles were about one GTX in nineteen. How many GTXs carried the Hemi has not been traced to any documented record.²

The GTX also went drag racing as a showroom advertisement. Sox & Martin's own history of its 1967 cars says the team moved away from the altered-wheelbase A/FX cars it had run for two seasons, and it quotes Chrysler racing boss Bob Cahill: “The last time I checked, we don't sell Fuel Altered Funny Cars.” Alongside a Hemi Belvedere II campaigned as an RO package car, the team raced a 440-powered GTX to promote Plymouth's new muscle car. The Belvedere II, not the GTX, won that year at the NHRA SpringNationals in Bristol, Tennessee, and the team says that victory launched its touring Supercar Clinic program.⁵

The first GTX set the terms for what came next at Plymouth. One year later the division launched the Road Runner on the same intermediate body, and Ate Up With Motor records that it was $559 cheaper than an equivalent GTX, with a standard 383 using the 440's heads and camshaft. The GTX stayed the dressed-up car with the bigger standard engine, and the Road Runner became the plain one with the cartoon horn. In 1967, though, the GTX stood alone: about 12,690 cars by a dealer-sales estimate, a 375-horsepower standard 440 and a Hemi option, and a road test that ran out of brakes.^3,2,1