Racing groups:
Pre-1940 Sports & Touring cars
1927-1951 Racing cars
1974-1980 Formula Atlantic (FAtl)
1981-1989 FIA Mfg. Championship & IMSA GTP
1973-1982 IMSA, GT, GTX, AAGT, GTU/GTO
1962-1967 Shelby Cobra
1974-1990 Stock Cars with disc brakes
1955-1962 GT cars
1960-1968 Sports Racing USRRC
1963-1966 GT cars over 2500 cc
1955-1961 Sports Racing cars under 2000cc
1958-1963 Formula Junior cars
1955-1961 Sports Racing cars over 2000cc
1947-1955 Sports Racing and GT cars
1961-1966 GT cars under 2500cc
1970-1979 Sports Racing cars under 2000cc
1966-1972 Trans-Am