MINOR CHANGES ON 1972 PLYMOUTH ROADRUNNER
The 1972 closely followed and carried over from the 1971 model with minor trim and detail changes. Front and rear facias changed of course, with a cleaner, more aerodynamic front grille and new tail lights to match the look. Side marker lights changed throughout the entire Chrysler lineup from flush-mounted to surface-mounts, and the ’72 Roadrunner was no exception. The optional rubber bumper guards now surrounded the tail lights and added a strip across the front bumper just below the grille. Leather and power seats were eliminated from the option sheet.
1972 PLYMOUTH ROADRUNNER – BAD NEWS ON ENGINES
By 1972, what had started out bad was getting worse. Continued adjustments needed to be made to make new cars meet ever-tightening regulations, and run on the crappy new gas. Compression ratios continued to drop. Plymouth was forced to lower rear end gearing (high numbers, numerically) to cope with waning performance, which is the bane of fuel economy. But there was no other way to get the cars to “go” with these new Smog-Dog motors. The tallest rear end gearing you could get was 3.55:1. News from the engine room was bad: The mighty 426 Hemi was gone for good. The 440 Six-Pack couldn’t meet smog regs and so was dropped at the end of ’71. The new top engine was a single 4-barrel 440 rated at 280hp (mind you, those are net horsepower now, not gross as before). The 383 big block V8 was bored out to 400ci to compensate for the drop in compression and thus performance. The 340 small block V8 was also available. For the first time, a 4-speed could be order with any of them.
1972 Plymouth Roadrunner INTERIORS
1972 PLYMOUTH ROADRUNNER GTX
GTX had ceased to be a stand-alone model, and this was was nothing more than an optional performance package for the Roadrunner. The Roadrunner GTX came standard with the top-line motor, a 400 wheezing out 280hp, backed by a 4-speed, came standard with more luxury and performance goodies that were optional on lesser models, and the obligatory stripe package and emblems. The Roadrunner GTX package ran from 1972 through the 1974 model year.