The 400 GT was introduced in 1966, which retained the same wheelbase as the 350 GT but featured an enlarged 3.9-litre version of the V-12 engine, thereby increasing power from 270 to 320 horsepower. Although a handful of early 350 GTs had featured a novel “2+1” seating pattern, the majority were configured in regular two-seater form. However, ever mindful of the benefits of broadening the appeal of its cars, Lamborghini—after producing just 24 examples of the two-seat 400 GT—opted to further modify its derivative into the 400 GT 2+2, the latter being publicly unveiled at the Geneva International Motor Show in March 1966.
Furthermore, the 400 GT 2+2 benefitted from other cosmetic and ergonomic changes; a larger rear luggage compartment, increased fuel capacity, quadruple headlamps, and revised lower front valance being notable examples. However, it was arguably in its transmission that the greatest technical improvement was made; the somewhat recalcitrant ZF gearbox of the 350 and 400 GTs being replaced in the 2+2 by a much smoother and quieter five-speed all-syncromesh unit of Lamborghini’s own manufacture.