The Duster was introduced in 1970 as a sporty version of the Plymouth Valiant. With a fastback roof and different taillights, it had a distinct look. The Duster 340 was the performance version with a 340 four-barrel rated at 275 horsepower, but there was also a Duster Twister model which had the slant six or a 318. The Duster 340 could outperform some bigger and more expensive muscle cars. In 1974, a lower performance 360 replaced the 340 engine. The original Duster ended production in 1976.