The talented Italian stylist Giovanni Michelotti was essentially Triumph’s house designer in the early 1960s. The Spitfire 4 of 1963 was a particularly nice effort on his part, far prettier than the big TR sports cars that he also penned. When the Standard Triumph works competition team fitted an aerodynamic hard top to the car for a highly successful campaign at the famed 24 Hours of Le Mans, the marketing people began to think about adding a neat little coupe to the Spitfire line.
The resulting coupe was indeed neat (looking a great deal like a 2/3-scale E-type) but the tiny Spitfire four-cylinder rendered the car woefully underpowered. Triumph substituted the smooth little 2.0-liter six from the Vitesse and thus had a fairly refined little GT to compete with the newly introduced 1966 MGB GT. That is refined until the limit of its grip was reached in a corner—the car’s fairly crude Triumph Herald-derived swing axle rear suspension resulted in appalling changes in camber and cars leaving the road hatchback first.
After an outcry from U.S. dealers (smarting from Ralph Nader’s bashing of the swing axle Corvair) Triumph rectified the situation with the 1968 GT6 Mk II (earlier cars became retroactively known as Mk Is, while the Mk II was referred to as the GT6+ stateside) which added a set of side vents, and a less attractive raised bumper in front to comply with U.S. laws. Emission controls became a part of the program in the U.S. for the first time and while the rest-of-the-world GT6 got a bit quicker, the U.S. models got slower.
The final changes came for the 1971 model year with the Mk III which got a simpler revised (but still effective) rear suspension and a general clean-up again by Michelotti to mirror the Kamm tail of the new Spitfire. It’s a bit of a toss-up as to which is prettier, the Mk I or Ml III. Both are quite nice.
By the early 1970s, the writing was on the wall for the GT6. The Datsun 240Z had burst onto the scene and it was an altogether better car in almost every measure. And while the Spitfire on which it was based soldiered on for another seven years, the GT6 was quietly dropped after 1973.
Today, GT6s are quite collectible because of the smooth little six and faux E-type styling. Parts support is quite good and the earliest cars while in the shortest supply are the most desirable.