1967 Plymouth Belvedere GTX 426 Hemi Convertible

Plymouth built 686 GTX convertibles for 1967, and only 17 of them carried the 426 Street Hemi, split roughly ten automatics to seven four-speeds. The $564 option brought a NASCAR-derived engine, a Dana 60 or heavy-duty 8.75 rear axle, and a maintenance schedule most owners underestimated badly. Nine out of ten GTX buyers took the 375-horsepower 440 instead, and most of them were making the right call. Read on for what a genuine Hemi GTX convertible has to prove on paper.

Plymouth spent the mid-1960s building cars that were fast in a way that seemed slightly embarrassed about itself, plain sedans and post coupes carrying far more engine than trim, sold to people who preferred their performance unannounced. Then, for 1967, the company tried something genuinely different. It took the same mechanical ferocity and dressed it properly, with chrome road wheels, a racing-style fuel filler, twin hood scoops, bucket seats, and a name that sounded like it belonged on a European grand tourer. Most buyers took the standard engine, which was already among the largest in America. A very small number checked a different box, and among those, an almost invisible fraction did it with the top down.

The GTX Was Plymouth Growing Up

The GTX arrived for 1967 as Plymouth’s first genuine attempt at a premium muscle car, built on the Belvedere platform but positioned deliberately above it. Standard equipment included the 440 Super Commando V-8 rated at 375 horsepower, heavy-duty suspension and brakes, bucket seats, and a distinctly upscale trim treatment throughout. The idea was to compete with Pontiac’s GTO on presentation rather than purely on elapsed time, and to charge accordingly for the privilege. It worked well enough that the GTX name survived through 1971, and it established the template Plymouth would use for everything from the Road Runner to the Hemi Cuda later on.

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The 440 Was Not the Consolation Prize

It is easy, in hindsight, to treat any non-Hemi GTX as the lesser car, and that reading does the 440 a genuine disservice. The Super Commando 440 made 375 horsepower and 480 lb-ft of torque, delivered low in the rev range, through a single four-barrel carburetor and hydraulic lifters that asked essentially nothing of the owner in return. On the street a 440 GTX was very nearly as quick as a Hemi car and considerably easier to live with day to day. Roughly nine out of ten GTX buyers in 1967 chose it, and the great majority of them were making the correct decision for how they actually used the car.

What $564 Actually Bought

The 426 Street Hemi option added roughly $564 to the sticker in 1967, real money against a convertible base price in the low three thousands, and it bought an engine derived directly from Chrysler’s NASCAR program. Two Carter four-barrels sat on an inline intake above hemispherical combustion chambers, with solid lifters and a factory rating of 425 horsepower that most engineers of the era regarded as conservative. It also bought a maintenance schedule. Valve lash needed periodic attention, the carburetors needed synchronizing, and cold-start behavior was a genuine acquired skill. The Hemi was never an option anyone took for convenience.

Seventeen Convertibles

Plymouth built 686 GTX convertibles for 1967 out of roughly twelve thousand GTXs in total, and of those convertibles, seventeen carried the 426 Hemi. Ten were built with the TorqueFlite automatic and seven with the four-speed manual, which makes a Hemi four-speed GTX convertible one of the genuinely mythic configurations in all of Mopar production. Numbers this small mean the surviving population is tracked essentially car by car by specialists and registries, and it also means the market punishes undocumented claims severely. Any GTX convertible presenting as a Hemi car needs a fender tag and broadcast sheet that agree with one another.

What the Hemi Dragged Along With It

Checking the Hemi box did not merely change the engine. Four-speed cars received the Dana 60 rear axle, automatics got a heavy-duty 8.75, and the whole car came with upgraded torsion bars, rear springs, and brakes to cope with the added mass and output. The Hemi itself weighed substantially more than the 440, which shifted the car’s balance forward and made it noticeably more reluctant to change direction, a real consideration in a convertible that was already the least rigid body style Plymouth offered. These cars were built to go straight, decisively and repeatedly, and to do everything else merely adequately.

Details That Identify a 1967

The 1967 GTX is distinguished by its simulated hood scoops, the pit-stop style chrome fuel filler cap on the left rear quarter, GTX badging front and rear, and optional sport stripes running along the lower body. Chrome road wheels were part of the intended look from the beginning. Inside, buckets and a center console were standard, with a woodgrain-effect dash treatment that separated it visually from the Belvedere it shared a body shell with. It is a restrained car by 1970 standards, with no wing, no shaker hood, and no cartoon graphics, and that restraint is a large part of why it has aged as well as it has.

The Convertible Problem

Convertibles have always been the difficult end of the Mopar restoration world. Body flex accelerates rust in the floors, the torsion bar crossmember, and the rear frame rails. Top mechanisms and their pump systems are expensive to correct properly rather than merely make functional. Correct interior soft trim for a low-production car is not something that sits waiting on a shelf. Add a Hemi with its unique exhaust manifolds, cooling package, and hood-to-air-cleaner clearance requirements, and the restoration cost curve gets steep very quickly. The cars justify the investment at current values, but nobody should approach one expecting a straightforward project.

Why This Configuration Sits at the Top

Among Chrysler’s B-body muscle cars, the 1967 Hemi GTX convertible sits in roughly the same conversation as the 1971 Hemi Cuda convertible, not because it is faster but because the production figures are small enough that the market treats each surviving car as a distinct asset with its own history. It also represents the moment just before Plymouth’s performance identity fragmented into the Road Runner’s deliberate cheapness on one side and the GTX’s premium positioning on the other. For one model year the same car was both the fastest and the nicest thing Plymouth built, and seventeen buyers ordered it without a roof.

What They Ran When New

Period road tests put a 440 GTX in the mid-14-second range at just under one hundred miles per hour on the narrow bias-ply tires of the day, with zero to sixty in roughly six and a half seconds. A Street Hemi car with proper gearing, tuning, and stickier rubber could be persuaded into the thirteens, but doing so required work that most owners never undertook. The gap between the two engines in ordinary use was narrow enough that magazines of the era regularly noted it, and wide enough at the top of the rev range that anyone who had experienced both understood immediately what the extra five hundred and sixty-four dollars had purchased.

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