1966 saw further refinement of the Mustang. The gauge cluster was redone to separate the Mustang from its Falcon roots while the 260 cid V8 was replaced with 2 and 4 barrel versions of the 289 cid V8. The Shelby GT-350 was still available, though its race image was being diluted by the addition of an automatic transmission, a choice of four colors, and special examples that were prepared for Hertz Rent A Car (known as Shelby GT-350H) for rental to weekend drag racers. Available on the GT-350 through 1968 was a Paxton supercharger which would boost horsepower by as much as 40%.
Production: 2D Hardtop: 499,751 Fastback: 35,698 Convertible: 72,119
Engines: 200 I6 120 bhp. 289 V8 200 bhp. 289 V8 225 bhp. 289 V8 271 bhp. (GT-350) 289 V8 306 bhp. (GT-350R) 289 V8 360 bhp.