While the Hardtop and Convertible body styles were introduced as unofficial 1964-1/2 model year offerings, the Fastback was the only 1965-1966 First Generation Mustang body style that actually began production for the 1965 model year (August 1964). 1965-1966 Ford Mustang Fastbacks were available with four engine options, the 120hp "T-code" 200 cubic inch (3.3L) inline six, the 200hp "C-code" 289 cubic inch (4.7L) two-barrel carbureted V8, the 225hp "A-code" 289 cubic inch (4.7L) four-barrel carbureted V8, and the top of the line 271hp "K-code" 289 cubic inch (4.7L) V8 that was fitted with a four-barrel Autolite carburetor. Depending on the fitted engine, Mustang Fastbacks were equipped with a 3 speed manual, 4 speed manual, or a 3 speed automatic, all of which sent power to the rear wheels. At the end of 1965-1966 Ford Mustang production, the updated 1967-1968 First Generation Ford Mustang was introduced.