The Road Runner
1968 Plymouth Road Runner The original muscle cars were moving away from their roots as relatively cheap, fast cars as they gained features and increased in price. Plymouth developed the Road Runner to market a lower priced, basic trim model to its upscale GTX . The earliest of the 1968 models were available only as 2-door pillared coupes (with a B-pillar between the front and rear windows), but later in the model year a 2-door " hardtop " model (sans pillar) was offered. The Road Runner of 1968-1970 was based on the Belvedere, while the GTX was based on the Sport Satellite, a car with higher level trim and slight differences in the grilles and taillights. Engine 1968 Plymouth Road Runner The standard engine was an exclusive 383 cu in (6.3 L) " Roadrunner " V8 engine rated at 335 bhp (250 kW) and 425 lb·ft (576 N·m) of torque . Its extra 5 hp (4 kW) rating was the result of using the radical cam from the 440 Super