The Road Runner convertible returned to the lineup for a second year in 1970. It’s seen here with the Code V21 Performance Hood Paint option atop the new domed hood (the Air Grabber scoop is shown closed). The F60-15 Goodyear Polyglas tires were introduced in 1970; it was the largest tire size offered on a Plymouth up to that point. (Photo Courtesy Mecum Auctions)
A view under the hood of a Code N96 Road Runner shows the rubber seal that goes around the Coyote Duster air cleaner, sealing off hot, undressed air from the colder, denser outside air that the scoop directs into the engine for more power. The front of the seal sits where an optional air conditioning compressor would have been installed, making the Code H51 Airtemp air-conditioning option unavailable with the Air Grabber option.
Underneath the hood of this 1970 Road Runner resides the 426 Hemi, the most exclusive, valuable, and powerful engine installed in this model. As you can see, it’s equipped with the N96 Air Grabber hood, Rallye Wheels, and the optional “Dust Trail” side stripes adorn the quarter panel, door, and fender. (Photo Courtesy David Newhardt)
The high-output 383-ci engine that was standard in 1968 remained for the 1970 Road Runner. This one wears aftermarket chrome valvecovers and an orange Mopar Electronic Ignition System control box on its firewall. Note the bottom of the Coyote Duster air cleaner, which fits flush with the air-scoop mechanism on the underside of the hood when the hood is closed.
The 426 Hemi was rated at 425 hp with 490 ft-lbs of torque; it was an $841.05 option. It’s seen here covered with unrestored patina and an aftermarket battery next to it. This car is equipped with an Air Grabber scoop (Code N96) as well as with non-power-assisted brakes. (Photo Courtesy David Newhardt)
Redesigned for 1970, the Road Runner’s all-vinyl bench seat incorporated the federally required headrests into the seatback. The taper toward the top allowed easier rearward viewing by the driver, something that Ford’s also-new-for-1970 high-back bucket seats didn’t have. (Photo Courtesy David Newhardt)
Another new feature for 1970 was the Rallye dash, borrowed from the Dodge Charger and featuring a standard 0-150–mph speedometer. The “Tick-Tock Tach” tachometer, which featured an electric clock at its center, was a $68.45 option (Code N85). (Photo Courtesy David Newhardt).
For an additional $14.05, the Bird’s plumage included optional High Impact colors such as Lime Light (seen here), Tor Red, Vitamin C Orange, In Violet, and Lemon Twist. Another vivid shade of green, Sassy Grass Green, joined the High Impact color selection in February 1970, as did the shocking-pink hue Moulin Rouge.
In 1969, the Road Runner hardtop was the top-selling two-door Plymouth, and the nation’s Chrysler-Plymouth dealers were optimistic that the 1970 version would sell strongly again. This one wears the optional paint color In Violet atop its freshened-for-1970 sheet metal, one of eight vivid colors available for an additional $14.05. (Photo Courtesy Mecum Auctions)
For many performance-car buyers, that was plenty. For others, the optional 440 Six Barrel offered more in the way of features and performance. Using the 440 Magnum as a base, the 440 Six Barrel used the same new-for-1970 thicker forged-steel connecting rods, molybdenum-filled top piston rings, and revised camshaft lift and duration that the 440 Magnum used, along with the 906 cylinder heads (so nicknamed from the last three digits of its factory casting number), which flanked a new intake manifold that was topped by three big Holley 2-barrel carburetors with mechanical linkage.
The new intake manifold was cast iron, instead of the cast-aluminum part sourced from aftermarket specialty company Edelbrock for 1969. Cost issues (namely involving the much-lower cost of cast iron compared to cast aluminum) and concerns that Edelbrock’s foundry didn’t have the capacity to support this option over a full model year led Chrysler to take it in-house for 1970. (Some early 1970 440 Six Barrels were built with leftover 1969 aluminum intake manifolds to use up the parts stock on hand.)
Using the simulated scoops pressed into the 1970 Road Runner’s rear quarter panels, the optional Dust Trail side stripes extended forward to the decal of the running bird on the front fender. The stripe appears to be dusty brown until light shines on it, which then reveals the stripe’s reflective gold-colored material. (Photo Courtesy David Newhardt)
Add a slight bump in compression from 10.1 to 10.5:1 (meaning that the best available pump premium gasoline was your only fuel choice, lest your engine “knock” from lack of octane and tear itself apart inside) and the 440 Six Barrel was good for a peak of 390 hp and 490 ft-lbs of torque. It was a great performance value if you look at how much extra it cost, compared to the 426 Hemi.
The horsepower and torque numbers for the 440 Six Barrel were reached at lower engine speeds than the Hemi’s, adding to the dual street/strip capability of the triple-carbed RB engine.
The 426 Hemi was Plymouth’s top performer since its 1-2-3 finish in its debut at the 1964 Daytona 500, and being put on the B-Body Plymouth option list in 1966. For 1970, its camshaft was switched from a solid-lifter one to a hydraulic-lifter stick, while not losing any performance as evidenced by its 425-hp rating, the same as for 1969.
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