Heart of the Pony: Ford's All-Time Top Mustang Engines 3
1969 Boss 429
The 1969 Mustang Boss 429 was the original monster Mustang, with a huge 429 cubic-inch engine recruited from the ranks of the factory-backed NASCAR teams.
The result was 376 "stated" horsepower under the hood of a street-legal Mustang. I say "stated" because in the case of the Boss motor, the engineers were obviously following the famous "under promise and over deliver" mantra, as it's been proven these big blocks had far more power on tap than advertised. Coincidentally, this approach seems to mesh nicely with the "win on Sunday, sell on Monday" philosophy famously associated with Ford's NASCAR efforts.
The Boss 429 would hold the bragging rights of being the most powerful factory-production Mustang for a phenomenal 30 years.