In 1972, the rules of the Marche Championship changed again, bringing to an end the age of 5-litre sports cars, usually built in at least 25 models. The new rules dictated that the races were to be reserved for the new 3-litre Group 6 cars. The 312 P lined up by Scuderia Ferrari was a distant relative of the 1969 312 P, substantially modified by the team of Mauro Forghieri. So much so that it was informally renamed 312 PB, due to its new 3-litre, 12-cylinder boxer configuration engine with 460 hp, fresh from Formula 1.
In the 1972 season, Scuderia Ferrari entered three cars, driven by fast and highly experienced drivers: Jacky Ickx, Mario Andretti, Brian Redman and Clay Regazzoni, later joined by Ronnie Peterson, Tim Schenken and Arturo Merzario. Even the rally champion Sandro Munari ran some of the races, as well as Helmut Marko and Carlos Pace.
Ferrari's had total supremacy, with ten victories in ten races. Each outing saw two Ferraris on the podium: in the eight one-twos it came in first and second place, while a victory and a third place were earned in Monza. The crowning moment was in Zeltweg, when the four Ferraris ranked in the first four places. Scuderia Ferrari won the 1972 Marche Championship.
Andretti and Ickx were the pair with most wins, at four. The Belgian driver triumphed twice more with Regazzoni and Redman. The latter won twice, the second time with Merzario, who also boasted a success with Munari in the Targa Florio.
This Sicilian victory led to a stroke of genius. Ferrari had the brilliant idea of deploying the rally champion outside his usual environment, and the Venetian – though not as fast as Merzario – showed his mettle with sports cars, too, both when road-racing in Sicily and in the 1000 Km in Zeltweg.
Peterson and Schenken also claimed two victories, testifying to the high quality of both drivers and cars. Moreover, Scuderia Ferrari won the 500 Km in Imola, not part of the World Championship, where Merzario triumphed ahead of Ickx. This category was something of a swan song for Scuderia Ferrari, as very soon the entire programme would be abandoned to shift the focus entirely onto Formula 1.