the Duster badge. The 1970 Duster was available in two models – the standard Duster and a performance-oriented Duster 340. Engine options were and versions of Chrysler's Slant Six, as well as the and LA-series V8s. At midyear, a Gold Duster trim package was added. The Gold Duster package came with gold badging, gold stripes on the sides and rear, wall-to-wall carpeting, pleated, all-vinyl seats, whitewalls, wheel covers, a deluxe insulation package, and a canopy vinyl roof. The Gold Duster was offered through 1975 of which 24,817 were equipped with the 318 engine. 1971 The Duster was a success for Plymouth, so much so that in 1971 Dodge requested and received their own version, the Demon. In response, Plymouth was given a version of the Dodge Dart Swinger 2-door hardtop named the Plymouth Valiant Scamp. For 1971, only small changes were made to the Duster. The "Valiant" fender badges and "Plymouth" grille logotype were deleted. A new trim package was released, called the Duster Twister. The Twister package presented the appearance of the Duster 340, but came only with the base I6 or 318 V8. The Twister's appearance package included special side stripes that mimicked the Duster 340 Wedge stripes, a matte-black hood, and the 340's special shark-tooth grille. A nonfunctional dual hood scoop and rear spoiler appearance package were available, as were high-back bucket seats and dual exhaust. A new electronic "breakerless" ignition became optional on the 340 V8 late in 1971 model year. In 1971, 186,478 Plymouth Dusters were built, with 12,886 equipped with the higher horsepower 340 cubic inch engines. 1972 The Duster was not changed significantly for 1972. New surface-mount sidemarker lights replaced the previous flush-mount items, the taillamps became larger, one-piece units. The power rating of the 340 V8 was reduced from to due in part to a reduction in compression ratio from 10.2:1 to 8.5:1, as well as changing the intake valves from to . All horsepower rating numbers, even on unchanged engines, decreased for 1972 due to a new rating protocol. Chrysler's electronic ignition became standard on the 340 models in 1972. Also, there was a 1-year only air cleaner that had a vacuum-operated door at the bottom to allow for additional airflow when the throttle is depressed. 1973 Following the design changes on the Valiant models, the Duster also received a new hood, grille, front fenders, bumpers, and taillights for 1973. The