Ferrari faced 1964 by focusing on increasing the displacement of its Sports cars, with a 3.3-liter (275P) and a 4-liter (330P). The 3.3 engine derived from the 250 with the bore increase from 73 to 77mm. Three new chassis (0818, 0820 and 0822) were prepared with the new P-64 specifications, and were equipped with either 3.3 and 4 liter engines, as needed. A fourth chassis, 0824, was used only in 1965. The cars of 1963 were also converted to the new engines: 0810, 0814 and 0816. The P-64s were also used by private teams, such as NART, Mecom Racing and the Maranello Concessionaires. For the official team, 1964 was one of the best years in its history: the Ferraris imposed themselves in Formula 1, in Prototypes (with the 275P and 330P) and in the GT with the GTO, despite the lack of homologation of the 250LM.