In 1965, Zagato was considered a top design company, so it is easy to understand why they selected an equally noble chassis to design and build a new body on.
This design became the Lamborghini 3500 GTZ, the new body was mounted on a 10 cm shortened chassis taken from the 350 GT, and was presented on the 1965 London Auto Show, finished in white over a black plastic (vinyl) interior, this was car number 0310 with engine number 0301.
The finished car looked rather awkward, the front of the car lacked personality, and overall proportions just weren't right, subsequently, only two cars were ever built, a white over black one (nr. 0310) and a silver over black one (nr. 0322).
The nr 0310 was later sold to ex-race driver Marchese Gerino Gerini who was also Lamborghini's official agent in Milan during that period, later he sold to car to a fortunate customer in Australia who had it converted to right-hand drive and repainted in red.
Recently this specific Zagato Lamborghini was bought by a German collector who shipped it to The Netherlands to undergo a full restoration, during which it will be converted back to left hand drive and repainted in a fresh red paint.
The Zagato records show two cars being built during November 1965, recently it was believed only the 0310 was actually built, but the second car did really exist with the chassis number 0320 and had engine number 0228 installed, it was driven by Mr Stanzani himself at first, later this one was sold to a customer in the United States. Rumours were this car was later destroyed in a rather big accident and was damaged beyond repair, note that this statement was never officially confirmed.
Some sources may state the engine of the number 0310 car was in fact one of the early 4-Litre engines instead of the normal 3.5-Litre unit but this was also not officially confirmed, as far as paperwork can show, this car still used the 3500 cc engine with repco pistons.
The 3500 GTZ isn't considered as one of the better Zagato designs, the design, which was executed by Ercole Spada, showed some resemblance with a Ferrari 25O GTO, but lacked the awesome looks and charisma of this berlinetta according to some people, note however that the structure line of these 3500 GTZ's was shared with the Alfa Romeo TZ 2.
It must be noted that these two cars actually represented the only relation between Lamborghini and Zagato, the latter was never contracted by Ferruccio, he liked the Bertone designs better, as almost all the Lamborghini designs to follow the 350/400 GT were executed by Nucio Bertone and his design team.
The LamboCARS.com extensive specifications chart on 3500 GTZ by Zagato ...