Ford's Boss 429: The Street-Legal Engine That Couldn’t Fit, Forcing Hand-Crafted Mustangs
Under NASCAR rules Ford had to sell a street version of the 429-cubic-inch engine, but the engine bay wasn’t built to accommodate it. Kar Kraft workers cut and reassembled every Boss 429 by hand to make them legal, resulting in fewer than 1,400 cars and helping cement the Boss 429’s legendary status in muscle-car history.