The GTX was based on the Belvedere, and was differentiated by a blacked out grille and special rear fascia, fiberglass simulated hood scoops with optional racing stripes, a chrome "pop-open" fuel filler cap, and a tachometer mounted on the center console.
The GTX was positioned as a "gentleman's muscle car". Standard was Plymouth's 440 cu in (7.2 L) V8 engine called the "Super Commando 440" rated at 375 hp (280 kW). Optional was Chrysler's 426 cu in (7.0 L) Hemi. A heavy duty suspension system was also standard.
