Sunday, June 6, 1971 – On a broiling day that saw some of NASCAR’s top stars sidelined by fatigue, Bobby Allison persevered to collect his 20th career win in the premier series with a victory in the Mason-Dixon 500 at Dover International Speedway. The temperature in Dover, Del. exceeded 90 degrees – inside the cars it was said to be as high as 140. Allison took the checkered flag a full lap ahead of the runner-up entry of Richard Petty.
• Fred Lorenzen was credited with the runner-up although he was replaced by Bobby Isaac with 60 laps remaining; Isaac had gotten out of his own car, which was taken over by Pete Hamilton. Petty was credited with a third-place finish – he was replaced by fellow Petty Enterprises driver Buddy Baker who had fallen out just past the halfway point with an engine issue.
• The race remains the only caution-free Cup race at Dover. In spite of a lack of yellow flags, the race still took 4 hr., 30 min. to complete.
• Allison’s Holman-Moody team had planned to run a Mercury in the race, but Ralph Moody said team made a last-minute call to switch and raced a Ford instead.
• To help cool their driver, the pit crew sprayed Allison with a water hose during pit stops.
• Allison’s winning average speed of 123.119 mph was a record for a 1-mile track.