Chevrolet Chevelle Z/16
What exactly is the Chevelle Z16? It’s a fully loaded regular Chevelle with a 396 V8 engine, a Muncie 4-speed gearbox, and heavy-duty suspension and equipment. Even some dealers weren’t aware that this option existed, and Chevrolet refused to market the Z16 for some reason, making this Chevelle a secret model (via Hemmings).

The Z16 was fast, but it was also expensive for a Chevrolet. That’s why they made only 200 of them. GM offered the car in the 1965 model year only, and most dealers didn’t even have the idea that Chevrolet built it.