The 1970 Plymouth Roadrunner featured a 116-inch wheelbase and hydraulic lifters for models that used the 426 Hemi engine. The vehicle came with three different engine options, including a 383 V8 engine producing 335 horsepower, a 440 V8 375 horsepower engine and the 426 V8 Hemi producing 425 horsepower. Models made in 1970 featured a new front and rear end that closely resembled the basic body of 1968 models. Hemi-equipped models can accelerate from 0 to 60 mph in 5.6 seconds.
The 1970 Plymouth Roadrunner saw several changes over previous versions including a new grille, a cloth and vinyl bench seats, redesigned hood, new front fenders and quarter panels as well as single-piston Kelsey-Hayes disc brakes. The 1970 models also featured non-functional scoops in the rear quarters. Vehicles were available as either a two-door coup or convertible with either a three-speed automatic or four-speed manual transmission.
The Roadrunner was a performance muscle car. Plymouth produced the Roadrunner from 1968 to 1980. A 1970 Roadrunner with a 426 Hemi engine also featured the Air Grabber hood that utilized a power-operated trap door to raise and lower a planed-off scoop. The 1970 Roadrunner possessed a 4,000 pound curb weight and a quarter-mile time of just 13.49 seconds at 106 mph.