High Quality Content by WIKIPEDIA articles! The 1964 World Sportscar Championship season was the 12th season of FIA `World Sportscar Championship` motor racing. It featured the 1964 International Championship for GT Manufacturers which was open to Group 3 GT cars and was contested from February 16, 1964 to October 11, 1964 over a twenty race series. Titles were awarded in three engine capacity divisions: