Boss versions of the Ford Mustang were conceived internally by the manufacturer to counter the success of the Chevrolet Camaro. In 1969, alongside the 302 with 4942cc engine, the Boss 429 was marketed, equipped with a 7033cc V8 engine (429ci) which gave a power of 375hp at 5200 rpm. The transmission was 4-speed mechanical. The Boss 429 remained in production until 1970, with 1358 units built, far fewer than those of the Boss 302 (8641).