Dolan made his debut at the 24 Hours of Le Mans in 2011.
The National made its professional support series debut at the 2003 12 Hours of Sebring.
Gardner made a one-off appearance at the 1998 24 Hours of Le Mans.
While Creighton Motorsport's chassis was not quite ready, the other two teams made their debut at the 12 Hours of Sebring.
The Bristol 450 made its race debut at the 1953 24 Hours of Le Mans race.
The 550 GT made one of its final appearances at the 2003 24 Hours of Le Mans.
The Alfa Romeo 33/3 made its debut in 1969 at the 12 Hours of Sebring.
The team also made their debut at the 24 Hours of Le Mans, taking a 14th place finish.
Following months of testing, the R8R made its racing debut at the 12 Hours of Sebring in 1999.
Strapped for cash, Dauer Racing made a last-ditch effort at the 24 Hours of Daytona in 1991, entering two 962s.