The very first Ferrari 365GTB4 was to be entered by Luigi Chinetti's NART in 1971. This car was conceived as a successor to the 275GTB4, and it was developed as a competition car for the customers willing to race such a car in the GT classes.The car had been christened Daytona after the marque triumph at the 1967 24 Hour race. The car would be a hit right off the bat. Many cars were modified by the customers themselves since Ferrari was too busy with the 312Ps and Formula 1 cars, which required the attention from Maranello. A relent less customers pressure would urge the factory to build five race cars. The car was pretty strong and reliable, and would prove also a great GT racer. This first series of race cars was the series 1 featured aluminum bodies, Plexiglas sides and rear windows and fiberglass doors besides a roll bar, as well as larger wheels and tires. A big front spoiler had been added to keep the car down at speed. The engines were also in a high state of tune. The series 2 featured more modifications, with an engine now producing around 400hp. Wider wheels were fitted, and the body was made of steel. Small fences had been added on the top of the front wings to help the car being more stable at speed. The last series of cars was produced by the end of 1972, with engines now producing around 450hp. Bigger brakes were added and the suspension had larger anti-roll bars. The cars would enter IMSA as early as 1973, with some fine results, but the most impressive account would be the 2nd place overall at Daytona in 1979 with John Morton and Tony Adamowicz behind the winning Porsche 935.
Such cars would be entered in IMSA from 1973 until 1981 or so, with a late entry at the Paul Revere race in 1983.