The Boss 429 was offered for the 1969 and 1970 model years in order to homologate the 429 engine for use in NASCAR. Production was completed by Kar Kraft of Brighton, Michigan, and each example was given a serialized number. Originally finished in red, this example was assigned serial number KK1791 and is said to have been repainted under prior ownership. Features include a hood scoop, front spoiler, louvered back glass cover, Boss 429 badging on the fenders,…
The Boss 429 was offered for the 1969 and 1970 model years in order to homologate the 429 engine for use in NASCAR. Production was completed by Kar Kraft of Brighton, Michigan, and each example was given a serialized number. Originally finished in red, this example was assigned serial number KK1791 and is said to have been repainted under prior ownership. Features include a hood scoop, front spoiler, louvered back glass cover, Boss 429 badging on the fenders, chrome bumpers, body-color sport mirrors, quarter panel scoops, reverse lights, and a dual-outlet exhaust that exits below the rear bumper.
Chrome 15″ Magnum 500 wheels are mounted with raised-letter 235/60 Cooper Cobra tires showing 2020 date codes. The Boss 429 model was equipped with revised control arms, a higher-rate front anti-roll bar than other Mustangs, a rear anti-roll bar, and staggered rear shock absorbers. Power-assisted brakes with discs up front and drums out back were standard on the 429, with the front brakes reinforced with heavy-duty hubs and rotors as well as oversized spindles. Power-assisted steering was also equipped from the factory.
The cabin features high-back bucket seats trimmed in black Clarion Knit vinyl along with a matching rear bench, color-keyed carpets, and simulated woodgrain accents on the dash, console, and deluxe door panels. The car was optioned with the Interior Decor Group–Deluxe and Visibility Group packages, and it features a Philco AM radio, a dash-mounted rally clock, deluxe seat belts, and courtesy lights for the glovebox, ashtray, and trunk.
The woodgrain-rimmed steering wheel frames a 120-mph speedometer, an 8k-rpm tachometer, and gauges for coolant temperature and fuel level. Controls for the choke and hood scoop are located on a steel bracket mounted on the lower dash area above the accelerator pedal. The five-digit odometer shows 32k miles, approximately 75 of which were added under current ownership. Total mileage is unknown.
Kar Kraft was commissioned by Ford to modify Cobra Jet Mustangs with a larger 429ci V8 featuring “crescent”-shaped combustion chambers. It came from the factory with an aluminum intake manifold and a four-barrel Holley 735-cfm carburetor. The engine was overhauled in 2005 and fitted with forged pistons, and the left valve cover and thermostat housing were repaired at that time. The selling dealer notes that the emission control equipment has been removed and is included in the sale.
An engine stamping featuring a 9F prefix corresponding to a 1969 Ford along with the last six digits of the car’s serial number sequence can be seen above.
Power is sent to the rear wheels via a four-speed close-ratio manual transmission and a Traction-Lok limited-slip differential with 3.91:1 gearing. The transmission is said to have been overhauled in 2005.