Stacy was originally from Kentucky. He served in World War II as a tank driver in the U.S. Third Army under General George S. Patton, an experience that placed him in some of the most demanding combat operations of the European theater before he returned to civilian life and found his way into motorsport.
Stacy made his first NASCAR Grand National start at Dayon Speedway in 1952, finishing twelfth of thirty cars. Deciding the MARC Series (the forerunner of ARCA) was a better path, he redirected his focus there. He narrowly missed the 1957 MARC championship, losing to Iggy Katona by just 4.5 points in one of the slimmest title margins in series history. From that near miss he built a dominant run, winning the series championship in 1958, 1959, and 1960. He recorded wins at Canfield Speedway in 1957, 1959, and 1960, and in 1959 opened the season by winning two of three events in April at Dayton and Canfield.
After a decade in the MARC Series, Stacy returned to NASCAR's Grand National ranks at age 40 in 1961, contesting 15 of the season's 52 races. He won the 1961 Southern 500 at Darlington Raceway, beating Fireball Roberts and leading 72 laps of the race — a victory at one of the sport's most demanding tracks and most storied events.
In 1962, Stacy delivered his most productive NASCAR season, winning three races. He won the Rebel 300 at Darlington Raceway, which was the final convertible race in NASCAR history, beating Marvin Panch. He then won the World 600 at Charlotte Motor Speedway by charging from 18th place through the field to defeat Joe Weatherly over the 600-mile distance. He also won the Old Dominion 500 at Martinsville Speedway, finishing more than three laps ahead of Richard Petty. The three wins were accompanied by seven top-ten finishes and five top-five results.
In 1963, Stacy did not win but produced nine top-ten and four top-five finishes, achieving a career-best 14th place in the final points standings. By 1964, at age 43, health issues began to limit his participation. He contested two more Grand National races before a final start at the Firecracker 400 in 1965, finishing 24th. His overall NASCAR Grand National career covered 45 races, with 24 top-tens, 13 top-fives, and four victories.
Stacy spent his final years in Florida, where he operated a car dealership. He died on May 14, 1986, at the age of 64. He was survived by his wife Mary and three children.
Stacy's career traces a path from the regional MARC Series, where he was the dominant force across three seasons, into NASCAR's highest level, where he proved competitive enough to win the Southern 500 and the World 600 — two of the longest and most prestigious events on the schedule. That he accomplished this after age 40, having come through World War II combat and spent nearly a decade in a secondary series, makes his record one of the more unusual in mid-century American motorsport. His 1962 World 600 comeback from 18th to first stands as one of the more dramatic individual race performances of its era.