The 1970 Ford Mustang Boss 429 remains one of the most significant American muscle cars of its era, combining NASCAR-inspired engineering with limited production and substantial collector appeal. This Grabber Blue example, identified by Kar Kraft serial number KK2288, is currently offered on Bring a Trailer with 4,028 miles shown and documentation supporting its originality and reported mileage.
NASCAR Engineering in a Roadgoing Mustang
Ford developed the Boss 429 to homologate its 429-cubic-inch V8 for NASCAR competition. Because the engine required extensive modifications to fit the Mustang’s engine bay, Ford commissioned Kar Kraft of Brighton, Michigan, to complete the conversion. Approximately 500 Boss 429s were produced for the 1970 model year, making surviving examples particularly desirable.
The engine features distinctive crescent-shaped combustion chambers, an aluminum intake manifold, and a four-barrel Holley 735-cfm carburetor. Factory-rated output was 375 horsepower. Power reaches the rear wheels through a four-speed manual transmission and a 3.91:1 Traction-Lok differential, preserving the direct mechanical character expected of a period performance car.
Competition Suspension and Period Styling
Finished in Grabber Blue over white vinyl upholstery, this Boss 429 retains its unmistakable late-1960s muscle-car presence. Exterior equipment includes 15-inch Magnum 500-style wheels wrapped in F60-15 Goodyear Polyglas GT tires, a functional front spoiler, and rear Sport Slats. A rear spoiler has also been fitted.
The chassis benefits from revised control arms, front and rear anti-roll bars, and competition suspension with staggered rear shocks. Power-assisted steering and brakes, including front discs and rear drums, were standard equipment. Heavy-duty front hubs, rotors, and oversized spindles further distinguish the Boss 429’s braking hardware.
Inside, white vinyl high-back bucket seats complement simulated woodgrain dashboard, console, and door-panel trim. Equipment includes a Hurst shifter, a Deluxe Rim-Blow steering wheel, an 8,000-rpm tachometer, and an AM radio.
Documented History and Collector Appeal
According to the selling dealer, the Mustang remained with its third owner in Northern California for nearly four decades. Boss 429 specialist Bob Perkins documented an ownership transfer around 1988, when the car reportedly had 4,011 miles. His letter also records the installation of the rear wing, reinstallation of emissions equipment, and engine-bay detailing. The sale includes a Deluxe Marti Report, owner’s manual, and Indiana title. Minor cosmetic imperfections are disclosed, including a small paint touch-up and a paint drip near a Boss 429 decal.
Offered through dealer consignment in Anaheim, California, this low-mileage Boss 429 combines scarce production, specialized engineering, and documented history. For collectors, its significance extends beyond horsepower: it represents Ford’s determined effort to bring NASCAR-derived technology to the street.
1970 Ford Mustang Boss 429 For Sale – Image Gallery
Source: Bring a Trailer
