The Ford 289, part of Ford’s Window small block engine family, was originally manufactured in 1963 and quickly became Ford’s stock sedan motor.
The 289 continued to evolve from 1965-1968. During this time, the engine saw several variations:
HiPo variants of the 289 were introduced in late 1963 and were available via special order. These were mostly seen in Mustangs, where they became an option in 1964.
The HiPo engine was engineered to provide better performance, both in general and at higher RPMs.