Born in Fruita, Colorado, the son of a Russian immigrant father and a German immigrant mother, Nab's family relocated to Idaho where they operated a farm. He quit school after the seventh grade and eventually drifted into mechanical work, taking jobs in a California shipyard, a jewelry shop in Idaho, and later at an Allis-Chalmers dealership before moving to Portland, Oregon, where he worked for his brother's roofing business and as a Dodge-Plymouth dealership mechanic.
While working at the Portland dealership, salesman Bill Amick invited Nab to prepare his car for racing. Nab's debut as a Cup Series crew chief came at the Arizona State Fairgrounds in May 1955, where Amick qualified on pole. A subsequent pole followed the next week in Tucson. In 1956, Nab was hired by Pete DePaolo's Ford factory-backed team and relocated to Charlotte, North Carolina.
When Detroit manufacturers withdrew factory racing support in 1957, the Ford team was reorganized as Holman-Moody and Nab stayed on. He guided Joe Weatherly to the Rebel 300 victory at Darlington in 1960. From 1961 onward, Nab worked primarily with Fred Lorenzen. Together they won at Martinsville, Atlanta, Charlotte, and Darlington across multiple seasons, including Lorenzen's dominant 1963 campaign where he and Nab won six times and became the first driver-crew chief combination in NASCAR history to earn more than $100,000 in a single season. Lorenzen followed that with eight victories in 1964.
A notable incident at the 1964 Rebel 300 illustrated Nab's instincts: team owner Ralph Moody ordered Lorenzen to pit with 30 laps remaining, fearing a tire would fail. Nab overruled him and kept Lorenzen out. Lorenzen won without a tire problem. Nab's dismissal was reversed days later.
Nab left Holman-Moody before the 1965 season to join Junior Johnson's team. The move delivered Johnson his most productive statistical season: 13 wins in 1965, a career high. Johnson retired at the end of that year.
Nab's most celebrated sustained run came in 1969 when he and driver LeeRoy Yarbrough put together one of NASCAR's greatest seasons, winning the Daytona 500 with a last-lap pass, then the Rebel 400, World 600, Firecracker 400, Dixie 500, Southern 500, and American 500 at Rockingham — seven of the sport's most prestigious races in a single year.
For 1972, Bobby Allison drove for the team and won 10 races under Nab's direction, finishing second in the Winston Cup standings. Cale Yarborough replaced Allison in 1973 and immediately won four races. In 1974, Yarborough and Nab won 10 more races. Their championship breakthrough came in 1976, when Yarborough won nine races and claimed the first Winston Cup title for both himself and Nab. During that season, Nab's crew attracted wide attention by completing a mid-race engine change at Pocono Raceway in 36 minutes; one week later they did it in 20 minutes at Talladega. Yarborough and Nab successfully defended the championship in 1977 with another nine victories.
Also in 1976, Nab prepared Janet Guthrie's car for the World 600 at the request of Junior Johnson, assisting Guthrie's effort to become one of the first women to qualify for a major NASCAR Cup race in many years. Guthrie qualified 27th and credited Nab's setup work.
After two consecutive championships, Nab accepted an offer from Harry Ranier's WIN Racing Inc., citing financial security. The team won the 1978 Talladega 500 with Lennie Pond, and Buddy Baker replaced Pond in 1979. Baker won the Atlanta 500 that March before Nab was temporarily replaced mid-season, with the substitute crew chief winning at Michigan. Nab departed Ranier Racing and spent the remainder of his career in intermittent crew chief and consultant roles for various teams, including a stint as crew chief for Mark Martin in 1982 and chassis work for Richard Petty's team in 1985. In April 1987, a consulting role with Harry Gant's team produced a pole position at Bristol in Nab's first race, validating that his expertise remained sharp.
Herb Nab died on October 29, 1988, from a heart attack at his home in Mooresville, North Carolina, at the age of 61. His peers called him "one of the sport's first superstar crew chiefs" and "the first of the really top chassis experts in NASCAR." He was inducted into the Mechanic's Hall of Fame in 1977, the West Coast Stock Car Hall of Fame in 2010, and the National Motorsports Press Association Hall of Fame in 2022. He received nominations for both the Motorsports Hall of Fame of America and the NASCAR Hall of Fame later in his legacy period.