1966 Lamborghini 400 GT ‘Interim’
Between Lamborghini’s original 350 GT and the more practical 400 GT 2+2 existed a brief transitional model that few enthusiasts know about.
The 400 GT ‘Interim’ represented Ferruccio Lamborghini’s effort to extract more performance from his company’s debut sports car while maintaining its pure two-seat configuration.
This rare variant retained the 350 GT’s sleek Touring bodywork and compact proportions but received significant mechanical upgrades.
The most notable change was a larger 4.0-liter V12 engine producing 320 horsepower, achieved by increasing the stroke of the original 3.5-liter unit designed by ex-Ferrari engineer Giotto Bizzarrini.
Lamborghini also addressed one of the 350 GT’s few weaknesses by replacing the notoriously noisy ZF transmission with a new, much quieter five-speed Lamborghini-built gearbox.
The updated drivetrain included a proprietary Lamborghini differential in place of the earlier Salisbury unit, improving both refinement and reliability.
Production lasted only from 1966, with just 23 examples completed before Lamborghini shifted focus to the four-seat 400 GT 2+2. This brief production run makes the ‘Interim’ one of the rarest early Lamborghinis.
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