The engine was a single overhead camshaft per bank 4.4 litre V12 unit, with factory type reference 217B, with a total cubic capacity of 4390cc, and a bore and stroke of 81mm x 71mm, with outside the vee sparking plug arrangement, fitted with a bank of three twin choke Weber 40 DFI/4 carburettors, with a twin coil and rear of engine mounted distributors ignition system, to produce a claimed 320bhp. The engine was coupled to a five speed all synchromesh gearbox, with drive taken through a propeller shaft to a rigid rear axle. This engine was based on the original Colombo “short” block design, and was subsequently upgraded and used in the 365 GTC/S and 365 GT 2+2 models.