[2] The first version, also known as 2500 Sport, was built in a single example and was obtained from a chassis type A6GCS/53 on which the 2,500 cc (150 cu in) six-cylinder engine of the 250F of Formula 1 was mounted, suitably adapted to the regulations of the cars.

He participated in some races of the 1954 season, such as the Mille Miglia and the Supercortemaggiore Grand Prix of Monza, but without obtaining significant results.

The front suspension was a coil spring with Houdaille hydraulic shock absorbers and a stabilizer bar.

The rear ones with transverse leaf springs, Houdaille hydraulic shock absorbers, and a stabilizer bar.

[6] The project gained new vigor in 1956 when a model of the car was assembled in Modena; it was an A6 GCS with the particularity of having the De Dion bridge on the rear suspension and the gearbox in the block with the differential.

Four examples were built: the intent was to maintain the agility of the two-liter sports car but with more power to take on the larger displacement rivals.

The debut took place during the tests of the 1000 km in Buenos Aires: the performances were promising, but it was still judged unripe for use in the race.

The front suspension was a coil spring with Houdaille hydraulic shock absorbers and a stabilizer bar.

Surprisingly, there are 250S in the entry and start lists for the 1954 Le Mans 24 Hours and the Monza 1000 km of the same year.

A year later, Jim Hall celebrated his first victory in a sports car race at Eagle Mountain.