After the Second World War, sports car racing emerged as a distinct form of racing with its own classic races….and from 1953, its own FIA-sanctioned World Championship…..when NASCAR’s Strictly Stock Division was renamed the “Grand National” division beginning in the 1950 season. Over a period of more than a decade, modifications for both safety and performance were allowed….and by the mid-1960’s….the vehicles were purpose-built race cars with a stock-appearing body. From 1962, sports cars temporarily took a back seat to GT cars….with the FIA replacing the World Championship for Sports Cars with the International Championship for GT Manufacturers. Through the 1960’s, as super speedways were built and old dirt tracks were paved….the number of dirt races was reduced. A breed of powerful hybrids appeared in the 1950’s and 1960’s…..which raced on both sides of the Atlantic….while featuring European chassis and large American engines from the early Allard cars via hybrids….such as Lotus 19’s fitted with large engines through to the AC Cobra. The combination of mostly British chassis and American V8 engines gave rise to the Can-Am series in the 1960’s and 1970’s. This series, based in the United States and Canada, featured lightweight prototype sports cars fitted with large, powerful production-based engines that produced speeds in excess of 200 mph….when Clubmans provided much entertainment at club-racing level from the 1960’s into the 1990’s….and John Webb revived interest in big sports prototypes with Thundersports in the 1980’s…..while Group 4 Grand Touring Cars and Group 5 Special Production Cars became the premier form of sports car racing from 1976….with prototypes going into a general decline apart from Porsche 936 domination at Le Mans….and a lower-key series of races for smaller two-litre Group 6 prototypes. The last NASCAR race on a dirt track was held on September 30, 1970 at the half-mile State Fairgrounds Speedway in Raleigh, North Carolina. From 1972 through 2003, NASCAR’s premier series was called the Winston Cup Series….which was sponsored by R. J. Reynolds Tobacco Company cigarette brand Winston. The changes that resulted from RJR’s involvement, as well as the reduction of the schedule from 48 to 31 races a year, established 1972 as the beginning of NASCAR’s “modern era”.