Slideshow: The Mustang Boss 429 is a special classic example of one of the best classic Mustang’s ever created.
Boss-9
The Boss 429 Mustang is a high-performance variant that was offered by Ford in 1969 and 1970. It was sometimes referred to as the “Boss 9.” There were roughly only 1,350 units ever produced. The inspiration for this variant came from NASCAR. During this time, Ford wanted to develop a motor to compete with 426 Hemi from Chrysler. Thus, the 429 was born. It contained a forged steel crank and forged steel connecting rods. A single Holley 4-barrel carburetor was mounted an on an aluminum intake. This behemoth pumped out a conservative 375 bhp and 450 lb-ft of torque. The Mustang’s body, however, was not wide enough to encompass the massive BOSS 429 engine and as a result, Ford hired Kar Kraft to modify existing 428 Cobra Jet Mach 1 Mustangs to properly fit the new BOSS 429 engine. Kar Kraft made extensive modifications to the Mustang, including widening the shock towers and extending out the inner fenders to allow this massive engine to fit. Each car was given a Kar Kraft “KK” number.
Photo: Top Speed