[1] The 350 GT was based on the earlier Lamborghini 350 GTV and was equipped with a 3.5 liter V12 engine and a 2-door coupé body by Carrozzeria Touring.

[3] The following month Ferruccio Lamborghini tasked engineer Giampaolo Dallara with developing a production version of Bizzarrini's 350 GTV grand tourer.

[3] Second, they started readying the 350 GTV for its late-October 1963 Turin Auto Show debut, where Lamborghini hoped it would raise interest in the eventual production 350 GT.

[5] The 350 GT shared a number of features with the 350 GTV prototype, including a four-wheel independent suspension, the quad-cam 3.5 liter Lamborghini V12, and an aluminium body.

A number of mechanical revisions and refinements were made due to the suggestions of the Neri and Bonacini racing development shop and test driver Bob Wallace.

The body was redesigned by Carrozzeria Touring, retaining the original profile while cleaning up details of the design to result in a more cohesive appearance.

[6] In order to fit his grand touring car with a smoother, more pleasant, longer-lasting engine that would be "good for 40,000 hard miles between services," Ferruccio had Dallara and Wallace de-tune a version of this prototype GTV motor for street use.

[4][8] While this 350 GT design work continued, the 350 GTV prototype was rushed to completion for the upcoming October 26 press meeting and the subsequent inauguration of the Turin Auto Show on the 30th.

[3][5] The 350 GTV was shown at the Turin Auto Show with the original Bizzarrini "racing" V-12 engine—with its downdraft webers, rear distributors, etc.—displayed alongside as it was not "adapted to the chassis.

[4][5] Lukewarm reaction to the car caused Ferruccio Lamborghini to postpone plans for immediate production and move on to introducing Dallara's new 350 GT design.

[3][4] The manufacture of the bodies was entrusted to Touring of Milan, who used their patented Superleggera method of construction to fix aluminium alloy panels directly to a tubular structure.

It had an aluminium body, a Salisbury limited-slip differential, four-wheel independent suspension, and vacuum servo-assisted Girling disc brakes all round.

The GTV chassis was unsuitable for a street car due to its lightweight construction and small door openings obstructed by tubing.

[3] The Lamborghini 350 GTS was a convertible-roof spider version of the 350 GT, first shown at the November 1965 Turin Auto Show.