A fully restored 1969 Ford Mustang Boss 429, one of the most coveted muscle cars of its era, is set to appear at Mecum’s January auction. The car represents one of Ford’s most ambitious performance projects, created not purely for street use but to satisfy NASCAR’s production requirements and bring a new big-block contender to the track. Developed around the S-code 429 cubic-inch V8 and paired exclusively with a four-speed manual transmission, the Boss 429 became an instant icon among Ford enthusiasts and collectors.
The model originated from Ford’s effort to challenge Chrysler’s dominant 426 Hemi in late-1960s NASCAR competition. To qualify the new semi-hemi engine for racing, at least 500 road-going versions had to be produced, prompting Ford to build a limited run of re-engineered Mustangs. The 1969 version totaled 859 units, followed by 499 in 1970. With just 1,358 ever built, the Boss 429 remains one of the rarest production Mustangs.
Because the engine was too large for a standard Mustang shell, Ford turned to Kar-Kraft in Michigan to modify the cars. The company widened the shock towers, relocated the battery to the trunk, and revised the suspension to accommodate the oversized V8. These modifications added weight and altered handling, but they were necessary to meet the homologation goal. Ford rated the engine at 375 horsepower, though period testing consistently showed far higher real-world output, estimated near 500 horsepower in street form and well over 600 in racing trim.
The example headed to auction was originally sold in Iowa and retains its factory equipment, including power steering, power front disc brakes, the competition suspension package, and the N-case 3.91 rear end. The RUGAE2-coded four-speed transmission remains in place, as intended for every Boss 429 built. The car recently completed a comprehensive restoration by Muscle Car Restorations in Oklahoma and has accumulated only 16 miles since the work was finished.
Now presented in show-ready condition, this Boss 429 offers a rare opportunity to acquire a historically significant Mustang engineered at the height of the horsepower wars. With interest in homologation-era cars continuing to rise, it is poised to draw strong attention when it crosses the Mecum block in mid-January.
