The Ford Mustang GT was first introduced for the 1965 model year as part of the 1965-1966 First Generation Ford Mustang. Only V8 powered Mustangs were eligible for the GT Performance Package, which included a variety of interior and exterior cosmetic upgrades such as a unique instrument panel that included additional gauges. In addition to the cosmetic changes, the GT package also included disc brakes, stiffer springs, a stronger front stabilizer bar, and quicker steering. Ford offered the GT package on all body styles, which consisted of the GT Hardtop, GT Convertible, and GT Fastback. While the most common engine for the 1965-1966 Mustang GT was the 225hp "A-code" 289 cubic inch (4.7L) four-barrel carbureted V8, the top engine offered was the revered "K-code" High Performance (HiPo) V8 that featured an Autolite four-barrel carburetor that gave the engine an output of 271hp. These engines were paired to either a 4 speed manual or the 3 speed 'Cruise-O-Matic' automatic transmission, both of which sent drive to the rear wheels. A total of 40,623 1965-1966 Ford Mustang GTs were built before the introduction of the 1967-1968 Ford Mustang GT.