275 series, between 1966 and 1968. They were equipped with a four overhead cam 3.3 litre V-12 engine, a development of the double overhead cam 275 engine used from 1964–1966. The later 275 models are often called "four-cam" cars to distinguish them from earlier 275 models. 275 GTB/4 Introduced at the Paris Motor Show in October 1966, the 275 GTB/4 (or 4-cam) used the same basic platform as the early 275 GTB with mostly mechanical improvements. The Scaglietti-built bodywork was largely the same as the series II "long-nose" 275 GTB, with the most visible difference being an added hood bulge with creased edges. Campagnolo magnesium alloy wheels sized 14x7 were standard equipment, while traditional Borrani wire wheels were a special-order option. The engine was the Tipo 226 3285.72 cc Colombo V12, derived from the earlier Tipo 213 275 engine with two valves per cylinder, but now upgraded with four overhead camshafts and six Weber 40 DCN carburetors as standard. This engine produced a claimed . In a departure from previous Ferrari designs, the valve angle was reduced three degrees to 54° for a more-compact head. The dual camshafts also allowed the valves to be aligned perpendicular to the camshaft instead of offset as in SOHC engines. The engine used a dry-sump lubrication system with a large 17 qt (16 L) capacity. Improvements from the series II 275 GTB were carried over to the 275 GTB/4, including the torque tube connecting the engine and transmission. In addition to the upgraded engine, the 275 GTB/4 had several minor improvements to the cooling system, exhaust and suspension. The 275 GTB/4 had a claimed top speed of . A total of 330 were produced from 1966 to 1968. In 2004, Sports Car International named the 275 GTB/4 number seven on the list of Top Sports Cars of the 1960s. 275 GTB/4S NART Spider The 275 GTB/4S NART Spider was a roadgoing two-seater spider version of the 275 GTB/4, 10 of which were built in 1967. Production of this car was initiated by Ferrari's North American dealer, Luigi Chinetti, who wanted a successor to the earlier 250 California Spider series. He asked Sergio Scaglietti and Enzo Ferrari to build a spider version of the 275 GTB/4, which Chinetti bought for approximately $8,000 each, and listed at $14,400 retail. These cars were informally named NART Spiders, referring to Chinetti's North American Racing Team. While the name