Lot #671 - The BOSS 429 is arguably one of the rarest and most valued muscle cars to date. The origin of the BOSS 429 comes about as a result of NASCAR. Ford was seeking to develop a HEMI engine that could compete with the famed 426 HEMI from Chrysler in NASCAR's Grand National Series. NASCAR's rules required that at least 500 cars be fitted with this motor and sold to the general public. After much consideration, it was decided by Ford that the Mustang would be the car that would house this new engine. The BOSS 429 engine was derived from the Ford 385 engine. 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. The mounts for the front suspension were chopped and displaced to create room for the block and exhaust manifolds. Next the battery was repositioned to the trunk and a stiff sway bar was added to rear end. In addition, a hole was cut in the hood and a manual controlled hood scoop was added. These cars were rated conservatively at 375hp, but the actual output was well over 500hp. The manufacturers and dealers only listed 375hp because of legal issues and rising insurance costs. To show just how special these cars were, they were given special NASCAR identification numbers that were placed on the driver's side door. Each car was given a Kar Kraft "KK" number. This car, KK 2503 was a Russ Davis Ford "Thunderbolt" race car driven by Bob "Quarterhorse" Martin. After the car was retired, it was stored inside his Southern California shop until restoration began in 2005. This is a very special and extremely rare matching numbers car that is documented with the Elite Marti Report, invoice, previous title and pictures of the restoration.