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1970-1976 Plymouth Duster


1970 Plymouth Duster 340

Fulfilling the Duster's raison d'etre was the 275-horsepower 1970 Plymouth Duster 340, originally conceived as the CK -- for Clark Kent.

The 1970 Plymouth Duster 340 featured a 340-cubic inch V-8 engine with 275 horsepower.
The 340-cubic inch small-block V-8 generated a healthy
275 horsepower with its four-barrel carburetor
and 10.5:1 compression ratio.

Outside identification was discreet: dual black side stripes mid-body that thickened slightly to mimic the swelled quarters, and two wide black stripes connecting the tail-lights.

Stuffing the 340-cubic inch, small-block V-8 underhood was the Duster's ticket to ride in Plymouth's elite Rapid Transit System.

The package included all the expected goodies, like high-flow cylinder heads with 10.5:1 compression; high-lift, overlap, long-duration camshaft; a single Carter four-barrel carb; high-rate .87-inch-diameter front torsion bars; .88-inch front anti-sway bar; heavy duty shocks; heavy duty, six-leaf rear springs; front disc brakes; and E70X14 raised white-letter tires mounted on 5.5-inch Rallye road wheels with trim rings. Transmission choices included floor-mounted three- and four-speed manuals plus Torque-Flite, all heavy-duty.

In its March 1970 issue, Car and Driver put the coupe through its paces, succinctly characterizing the Duster 340 as a "reroofed Valiant with a performance engine, priced to sell ($2,547)." C/D clocked 0-to-60-mph times of 6.2 seconds, with top speed pegged at 120.

Regarding the standing quarter-mile, it reported, "A 14.72-second ET is better than any stock 'Cuda we've tried and a swarm of big-in-cost cars." But the testers were less impressed with the handling, reporting severe understeer that led to plowing in turns. "With all that rear overhang and the narrow rear track, we were lucky it handled at all," says Weiss.

The 1970 model-year production totaled 24,817 Duster 340s compared with 19,515 'Cudas. In fact, the Duster 340 outsold the 'Cuda 340/383 in each subsequent model year, and by healthy margins, proving the viability of the Duster concept.

Annual volumes for this hottest Duster remained in the 13,000- to 16,000-unit range right through 1973.

"One reason is that Duster 340 buyers -- mostly young men -- were able for a period of time to beat the deal-killer $1,200- to $1,500-a-year insurance rates with a bit of subterfuge," says Wiess. "Queried about their new purchase, these guys were able to obtain decent rates by telling their insurance agent, truthfully, 'I'm buying a Valiant two-door sedan.' Eventually, of course, the agents caught on and began asking, A Duster?' And then, 'six or V-8?' And finally, 'which V-8?' By that time, the game was over."

The 1970 Plymouth Valiant Duster was popular in the marketplace. Find out why when you turn to the next page.

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