The Plymouth Superbird was a highly modified, short-lived version of the 1st generation Plymouth Road Runner with well-known graphics and horn sound. It was the factory's follow up stock car racing design, for the 1970 season, to the Dodge Charger Daytona of 1969, and incorporated many engineering changes and modifications (both minor and major) garnered from the Daytona's season in competition. Generally accepted production numbers are 1,920 SuperBirds built and shipped to United States dealers, with anywhere from 34 to 47 allegedly heading to Canada. Three engines were offered on the Superbird, the 426ci Hemi V8, 440ci Commando V8, and the 440ci Six Pack V8.