The Ford Mustang, introduced in 1964, became an overnight sensation and the most successful model launch in automotive history. Its styling was fresh and modern, and combined sporty performance with personal luxury. Spawning a new 'pony car' market segment, the Mustang's appeal was further enhanced by its broad option list, allowing buyers to specify anything from a coupe to a fully equipped convertible. During Ford's 'Total Performance' era of the 1960s, the Mustang's options list included a wide range of powertrain combinations from inline sixes to the high-winding 289 V-8 engines in solid-lifter tune. Both manual and automatic transmissions were available to suit any driving style. With its shortened rear deck, an extended hood, and sporty bucket seats, the Mustang could be configured as a family sedan for grocery-getting purposes, or outfitted with enough features to satisfy the performance enthusiast.

Production of the Ford Mustang began five months prior to the start of the 1965 production year, with the early production versions often referred to as '1964½ models.' They were, however, advertised, titled, and VIN coded by Ford as 1965 models. Production began in Dearborn, Michigan, on March 9th of 1964 with the public introduction occurring on April 17th, 1965 at the New York World's Fair. Total model year production lasted eighteen months with more than one million Mustangs built.

The first 121,538 Mustangs built had unique features that have earned them a distinction with purists as '1964½' Mustangs. The list includes horn rights with the 'Ford Falcon' logo covered by a trim ring with a 'Ford Mustang' logo. Later cars had alternators instead of generations, a larger 200 CID six-cylinder engine (up from 170 CID), and a larger 289 CID V8 (up from 260 CID). Early six-cylinder cars had 4 lug 4.5x13 inch wheels and 13x6.5 tires. Optional whitewall tires measured 7.00x13. All 8-cylinder engines used 5 lug pattern on their rims. Optional on V8 cars were 14 x 14.5 rim and 6.50x14 tires. Mustangs equipped with V8 engines, beginning in 1965, used 4.5x14 rim and use 6.95x14 tires. The 15x5 wheels were an option and used 5.90x15 tires. The 15-inch opti9on was later dropped and later-built HiPo cars were equipped with 14-inch rims and dual red line sidewall tires.

All 1964 and 1965 built Mustangs have the '5' in the first place of the VIN. 1964.5 built cars have engine codes D, K, U while the 1965 built cars have a C, T, or A. Less than one percent of the 1964/65 production year were the K-code convertibles. The K-Code engine was first introduced by Ford in 1963 and used in the Fairlane, Falcon, and Comet. It first became available in early 1965 (sometimes referred to as the 1964 ½) Mustangs. Each K-Code Mustang had a special badge on its front fenders that read 'HIGH PERFORMANCE 289'. K-Codes were not available with power steering, air conditioning, or automatic transmission (until the 1966 model year). Prior to 1966, K-Code Mustangs were equipped with a four-speed only. K-Codes differed from the other D, C, and A code 289 engines, featured in the 1965 through 1967 Mustangs, with upgraded pistons, carburetor, lifter heads, connecting rods, and cylinder heads. Additionally, they had the chrome air cleaner and valve covers, and '289 High Performance' lettering atop the air cleaner, a high-performance clutch, driveshaft, rear differential, and suspension. The modified K-Code engine was the first engine used by Carroll Shelby in his Shelby GT350 Mustang. The GT350 Mustangs wrestling away the SCCA B-Production road racing dominance from Chevy's Corvette, which it did for three years straight from 1965 through 1967.