A high-performance version of the 289 engine was introduced late in the 1963 model year as a special order for Ford Fairlanes. The engine is informally known as the HiPo or the K-code' (after the engine letter used in the VIN of cars so equipped). Oddly, this engine was introduced in 1963 as the only 289 engine available in the intermediate Fairlanes. Lesser-powered cars had the 260 engine in that year. Starting in June 1964, it became an option for the Mustang.