 The win was Petty's second victory of the season.The 1966 season marked the return of the Chrysler Hemi engine in NASCAR competition, while Ford took a one-year leave from competition before realizing that the ploy was detrimental to their sales.The 1966 Daytona 500 was the fifth event of 49 in the 1966 season, which included the two qualifying races for the 500.