The Ferrari 312PB is one of the Ferrari entries the open record knows by name, and by little else. That is not nothing: a name in the catalogue is where a car's story starts to be recoverable. Its designer of record is Mauro Forghieri / Giacomo Caliri.
How it came about
The Ferrari 312 PB was a Group 6 prototype sports car introduced in 1971 by Italian carmaker Ferrari. It was officially designated the 312 P, but often known as the 312 PB to avoid confusion with a previous car of the same name. It was part of the Ferrari P series of Prototype-Sports Cars but was redesignated as a Group 5 Sports Car for 1972.
The hardware
it is rated at 460 bhp @ 10,800 rpm. Kerb weight is 665 kg. Power-to-weight lands near 692 horsepower per tonne, which is hypercar territory, where the limiting factor is the tyre, not the engine. These are manufacturer figures carried by Wikipedia and Wikidata, not road-test measurements.
Family and rivals
Where it sits in Ferrari's history is not in doubt: the Ferrari 312 P came before it; the Ferrari 333SP followed it. Its Ferrari stablemates include the 250 GTE and the 328 GTS.