In 1955, Ferrari’s faith in four and 12-cylinder cars began was under question by Lampredi who designed a 6-cylinder engine. The body and chassis was similar to that from the Mondial Series II.
The first six-cylinder was raced at the 1955 Buenos Aires 1000km in January. Known as the 376 S, 280 bhp was possible from the 3.7-liter engine. After Piero Trauffi won the Giro de Siclia, the cars were outfitted with a 4.4-liter engine that was one of most powerful in 1955.
Called the Tipo 121, the 4.4-liter engine was capable of 360 bhp. Fed by 58mm Weber carburetors, three of these engines were fitted into cars for the 1955 season. Eugenio Castellotti drove a 735 LM at the Mille Miglia.
All three 735 LMs were sent to the 24 Hours of Le Mans