THE LAST DETAIL: An appreciation for the small stuff turned this big, bad Boss 429 into a like-new muscle car

January 4, 2018
Posted by Barrett-Jackson

Written by independent automotive journalist Steve Statham

Crossing the block at No Reserve as Lot #1410 on Saturday, January 20, at the 2018 Barrett-Jackson Scottsdale Auction is this 1969 Boss 429 Mustang.

When it comes to the most desirable American muscle cars – and a Boss 429 Mustang surely belongs in that group – it’s the details that separate the mundane from the highest-quality offerings.

The Wimbledon White matching-numbers 1969 Boss 429 Mustang (Lot #1410) to be offered at No Reserve during Barrett-Jackson’s Scottsdale Auction, January 13-21, illustrates that observation perfectly. The restoration was performed with painstaking attention to detail. “Every part, piece, wire, bulb, nut and bolt has been meticulously restored on this car,” the seller says. “Only the best went into this restoration, including new exhaust, ECS glass and decals, fully restored Tachman gauges, clock and cluster.”

That level of detail is justified when tackling a Boss ’9. Built for only two years, a mere 857 were made in the car’s debut year of 1969, and not all of them have survived into the 21st century – even fewer with the original drivetrain intact, like this example. The car achieved its fame thanks to its race-bred pedigree and the eye-popping spectacle of its massive semi-hemispherical “crescent” cylinder heads topping the big-block engine.

The Boss 429 Mustang’s sole reason for being was to homologate the Boss 429 engine for NASCAR racing, where engines were required to be available in production cars to qualify as a “stock car” motor. The Boss 429 V8 was actually used in the Torino in NASCAR, but the decision was made to put the street engine in the Mustang for marketing reasons. The engine did its part in NASCAR Grand National racing, though, helping to propel Ford to the 1969 Manufacturers’ Championship and David Pearson to the Drivers’ Championship in a Ford Talladega.

Known for its massive ports and valves that helped it breathe at racing speeds, the Boss 429 V8 needed to be detuned to operate in normal street traffic. Even so, it was factory-rated at a stout 375 horsepower and 450 ft/lbs of torque. Each 1969 Boss 429 Mustang was fitted with a Traction-Lok differential and close-ratio 4-speed to handle the power.

The Boss 429 had so many unique attributes that it couldn’t even be built on a factory assembly line with other Mustangs. Ford shifted production to Kar Kraft in Brighton, Michigan, where, among other modifications, the specialty shop replaced the stock shock towers with reinforced pieces that delivered more room, installed a thinner brake booster, and relocated the battery to the trunk to free up under-hood space and improve weight balance.

Visually, the Boss 429 Mustang was instantly recognizable by its large functional hood scoop and chin spoiler. More subtle modifications included beefier spindles, relocated A-arm mounting points, thick front and rear sway bars, staggered Gabriel rear shocks, and fenders modified to accept the larger wheel and tire package.

The Kar Kraft legend is well known by Ford enthusiasts, but this Boss 429’s reconstruction to exact factory specifications was, if anything, even more meticulous. The body was stripped, dipped and e-coated, and put back together with superior panel fitment. “The hood, decklid, and doors open and close effortlessly,” the seller states. The undercarriage is as clean as the topside. All brightwork has been professionally restored and polished. The rear end, suspension and 735 cfm Holley carburetor were also professionally restored.

One functional but invisible upgrade was the switch to TM Enterprises cylinder heads. These replica heads mirror the factory heads externally, but have superior flow characteristics, are made of stronger aluminum and use head gaskets instead of the original O-ring design.

As you’d expect from a car that has received so much attention, it comes with full documentation, including Marti Report, Eminger letter, original Window Sticker, owner’s card, Boss 429 newsletters, Kar Kraft book, photos and Boss 429 Registry showing its been under the same owner for the last 17 years. When it comes to detailing, all of that is the cherry on top.

For up-to-date information on this vehicle, click HERE.