John Delphus McDuffie Jr. competed in the NASCAR Winston Cup Series from 1963 to 1991, collecting 106 top-10 finishes during his career, despite never finishing on the lead lap of any race in his career, and holding the record for the most starts in NASCAR's top level without a win with 653. He died in a racing accident during the Budweiser at The Glen at Watkins Glen International in 1991.

​

After attending his first race in Bowman Gray Stadium at the age of ten, McDuffie was inspired by racers Curtis Turner, Glen Wood, Billy Myers, and others to become a race car driver. His racing career started in dirt track racing. He picked the No. 70 early on because it was easy to paint and easy to remember.

​

McDuffie won several small races throughout the Carolinas including a track championship at a small dirt track near Rockingham, North Carolina. McDuffie made his NASCAR Grand National (now NASCAR Cup Series) debut in 1963 at the Racing Association of Myrtle Beach, Inc. Speedway near Myrtle Beach, South Carolina driving Curtis Turner’s old 1961 Ford. Though McDuffie was an expert dirt track racer, he never had similar success in NASCAR's premiership. His best NASCAR finish came at the Albany-Saratoga Speedway, in 1971, where he managed to finish third. 

​

Meanwhile, his first last-place finish came at the 1963 Pickens 200. In 1978, McDuffie won the pole position for the Delaware 500, his only pole position in Winston Cup competition. Normally a low-budget independent, McDuffie entered into a partnership with Donald Magnum and purchased a chassis from Richard Childress Racing. McDuffie in 1982 also made a start in the final race of the season at Riverside in Junior Johnson's second car, which was entered to protect Darrell Waltrip, who was on his way to winning that season's championship; If Waltrip had an accident in practice or qualifying, McDuffie could relinquish the second car to him and Waltrip would not jeopardize his championship hopes by missing the race.

​

In the 1988 Daytona 500 qualifying race, McDuffie received second- and third-degree burns in an accident after he raced without fireproof gloves because they were stolen before the race.

​

One day before his fatal accident at Watkins Glen International, McDuffie won a celebrity race in Owego, New York, at the Shangri-La Speedway, not far from Watkins Glen.

McDuffie is still the record holder for the most starts in NASCAR's top touring series without recording a win. His 653 starts rank him 22nd all-time through the end of 2018. McDuffie held the series record for the most last-place finishes with 32 until Joe Nemechek surpassed him in 2014.

​

In 2016, Front Row Motorsports and Landon Cassill honored McDuffie with a tribute paint scheme during the throwback weekend at Darlington Raceway complete with sponsors that sponsored McDuffie's racing effort.