This car was the first BB prepared for competition. Deployed by the NART team, it made its debut at the 1975 24 Hours of Daytona, before continuing its season at Sebring, Road Atlanta and Lime Rock. After a one-year break, she was seen again at Le Mans in 1977, again with NART. In 1978, after the Daytona and Road Atlanta races, the BB 18139 was entered in the 24 Hours of Le Mans by O'Flynn with a 5-liter engine. The last two racing appearances of this BB were at Watkins Glen in 1978 and Riverside in 1984.