Ford Mustang HO
In 1972, Ford discontinued Boss 351 and Cobra Jet Mustangs while Shelby models were killed two years prior. However, the performance Mustang buyers were given a choice, and Ford offered the HO model. HO stood for High Output, a kind of Boss 351 for 1972.

It featured a performance 351 V8 rated at 275 HP, which was healthy for early ’70s standards. In the end, Ford only made about 60 of those interesting machines in all three body styles (via Motor Trend).