The Duster was not changed significantly for 1972. New surface-mount side marker lights replaced the previous flush-mount items, the tail lamps became larger, one-piece units.
For 1974, Plymouth replaced the 340 with a 360 cu in (5.9 L) version of the corporate LA-series V8, with lower performance due to U.S. government-imposed emissions regulations. The 1974 "E58" 360 engine produced 245 hp (183 kW).
Following the design changes on the Valiant models, the Duster also received a new hood, grille, front fenders, bumpers, and taillights for 1973. The taillights on previous years mounted from the inside and had a flush appearance.