 | The Boss 429, the 'Boss 9', is one of the rarest and most valued muscle cars from the era. The origin of the Boss 429 came about as a result of Ford’s desire to compete in the top NASCAR series. Ford was seeking to develop a Hemi engine that could compete with the famed 426 Hemis from the Mopar camp - the 426 Hemi Charger Daytona and the Plymouth Superbirds. The Boss 429 cu. in. OHV V-8 engine was rated at 375 HP while actual output was believed to be well over 500 HP. |
 | In 1969 there were 859 Boss 429s made by Ford, two of which were Cougars for the Lincoln/Mercury Race Division. There were five different colors available and the only color for the interior was black. |  |
 | #1 Concours examples trend around $515k according to Haggerty. Condition #1 vehicles are the best in the world. |
 | In 2015 a 1969 Ford Mustang Boss 429 with a scant 120 miles on the clock sold for $247,000 That number would likely be much higher today. |  |
