Although the European sports cars, like Lamborghini, Ferrari and Porsche, are some of the most expensive you’ll find, it’s ironically one of the more affordable - at the time, of course - produced by the master of blue collar automobiles, Ford, that stands out above all when you speak about classic. The 1966 Mustang GT350 has one of the biggest fan bases on the planet.

Why is this model Mustang so popular among car enthusiasts? Well, perhaps you’ve heard of this car before and just weren’t aware of it. Can anyone say “Shelby”?

When Ford first released its muscle-slash-pony-style Mustang sports car, the crowds loved it but longed for something a bit more powerful. In 1965, Ford began working on a Mustang variant that to this day is one of the most popular automobiles of all time. The Shelby Mustang has appeared in books, movies, songs and, of course, on nearly every road across the globe.

To know what made the Mustang Shelby GT350 so special, you’d have to look at Ford’s total body of work leading up to the release of the 1966 model.

Carroll Shelby designed these cars, but they weren’t known as “Shelby’s” right away. Because Carroll had also produced the Cobra line, and the 1966 bore the Cobra emblem, there was a bit of confusion.

It isn’t until later, when the Shelby became a legend, that the automobiles were properly identified despite their Cobra emblems.

The 1965 model of the Shelby Mustang GT350 was the first released, but it was the 1966 that would become the legend. The 66 was an overall improvement, turning an already good car into a great car. The mirrors were redesigned, and the now iconic side-scoops were added. The 1966 also had a further modified K-Code engine, giving them more horsepower.

1966 was also the year that Shelby diversified the color options. Now, of course, color options might seem like a trite thing to be particular over, and people today will spend more money for the original color car, but the white body with blue stripes was dated by 1966. Shelby started releasing cars in blue, black, green and red.

Other changes to the Shelby Mustang GT350 included rear quarter-panel windows that replaced the extractor vents. Also, to market the car to a broader base so everyone could enjoy the power, Shelby changed the transmission and provided a 3-speed automatic to go along with the 4-speed manual.

The battery also moved alongside the engine, allowing for more trunk space, and a folding rear seat was now an option. The dark blue-painted engine blocks in the 1966 Shelby model were also more stylish and appealing, although adding nothing to the performance.

Eventually, the Shelby line stopped converting the Shelby American K-Code engines into GT350 engines and started putting in a 289 cubic inch 4.7 liter V8.

The many options available, including convertible tops, various colors, different engine types, and even different body styles, have helped to make the Shelby so popular today. There’s no one “set” 1966 Mustang GT350. They’re all popular and valuable. It all depends on which collector likes which style.