1966 Firecracker 400 from Daytona International Speedway | NASCAR Classic Full Race Replay

The 1966 Firecracker 400 took place on July 4 at Daytona International Speedway, where 40 drivers tackled 160 grueling laps. The event earned a landmark place in stock car history as the very first NASCAR race to feature a rear spoiler—an aerodynamic innovation installed by Dodge engineers that dramatically improved high-speed handling and downforce on the track's steep high banks.