The Legend of the Ultra-Rare Boss 429 Cougar

During the zenith of the muscle car era, acquiring a street-legal race car directly from a showroom floor was often a feasible reality. This was largely due to NASCAR regulations requiring manufacturers to sell at least 500 units of a specific car and engine combination to the public for it to be eligible for competition. Ford, aiming to challenge the dominant 426 HEMI, responded with the iconic 1969 and 1970 Boss 429 Mustangs. Fewer than 1,400 of these specialized Mustangs were produced, involving significant engineering effort to accommodate the massive engine, making them some of the most coveted Mustangs ever. However, even more valuable and significantly rarer were the two unique Mercury Cougars factory-fitted with the formidable Boss 429 Cougar engine setup. What became of these mythical machines?

Mercury’s Cougar: The Mustang’s Sophisticated Sibling

Introduced in 1967, the Mercury Cougar was positioned as “the gentleman’s muscle car.” Essentially a restyled Mustang featuring a longer wheelbase, it stood out in the Ford lineup as a model exclusively available with V8 power. Initially, buyers could choose between the 289 or 390 cubic inch engines. By 1970, the engine roster had expanded significantly, offering the 302, Boss 302, 351 (both Windsor and Cleveland variants), and the potent 428 Cobra Jet.

Through 1973, the Cougar often mirrored the Mustang’s performance options and identity. A major shift occurred in 1974 when the Cougar transformed into more of an entry-level personal luxury car, abandoning its muscle car roots. Simultaneously, the downsized Mustang II debuted, notably without a V8 option initially. Yet, conspicuously absent from the Cougar’s official options list during its prime muscle years was the Boss 429 engine, available in the Mustang for the ’69 and ’70 model years.

A Secret Project: The Birth of the Boss 429 Cougar

While never a regular production option, Ford did indeed commission the creation of exactly two 1969 Mercury Cougars powered by the legendary semi-hemispherical Boss 429 engine. These weren’t standard customer orders; Ford sold both vehicles for a symbolic $1 each to two prominent drag racers: “Dyno Don” Nicholson and “Fast Eddie” Schartman. Designated by Mercury as special “clinic cars,” these unique Boss 429 Cougars served a promotional purpose, touring dealerships to educate Ford technicians and enthusiasts about maximizing horsepower and performance.

Kar Kraft’s Challenge: Fitting the Beast

Similar to the Boss 429 Mustangs, preparing the Cougars to accept the massive 429 engine required extensive modifications. Both cars were sent to Kar Kraft, Ford’s specialty vehicle engineering facility in Brighton, Michigan. The Boss 429 engine’s “semi-HEMI” head design resulted in a very wide powerplant. To create the necessary clearance, Kar Kraft engineers had to relocate the shock towers outwards by one inch on each side, adding two crucial inches to the engine bay width. Additionally, the lower A-arms were lowered by an inch. Even with these changes, a massive, functional hood scoop – the largest ever fitted to a factory Mustang or Cougar – was essential to allow the hood to close over the tall engine. The battery also had to be relocated to the trunk to make space. These engines were imposing, even in an era defined by big-block power.

Technician working on the engine bay of Fast Eddie Schartman's Boss 429 Cougar, showcasing the modifications needed.

On the Road: Racing, Clinics, and Modifications

The paths of the two Boss 429 Cougars diverged slightly after delivery. “Dyno Don” Nicholson quickly removed the Boss 429 engine, replacing it with the even rarer Ford 427 SOHC “Cammer” engine, and painted his Cougar red. “Fast Eddie” Schartman retained the Boss 429 powerplant and the car’s original white paint but updated its appearance by converting the front end with a 1970 Cougar hood and grille assembly. Both cars utilized lightweight fiberglass front-end panels, a modification that technically rendered them ineligible for the Super Stock racing class they were ostensibly built for. Reports suggest, however, that the cars weren’t exceptionally fast in their initial configuration, so their class eligibility wasn’t heavily scrutinized, and they saw limited track time. Both vehicles were supposed to be returned to Ford upon completion of their promotional duties, likely destined for the crusher. Intriguingly, neither car made it back to Ford, and both seemingly vanished.

Fast Eddie Schartman's white 1969 Boss 429 Cougar featuring a modified 1970 front clip and hood scoop.

Lost to Time, Found by History

Like many legendary muscle cars, the two Boss 429 Cougars faded into obscurity for a period. Unlike the Boss 429 Mustangs, which received a unique “Z” code in their VIN to denote the special engine, these Cougars were built from standard “R-code” Cougars. The R-code signified the powerful 428 Cobra Jet engine – a rare and desirable option in its own right, but distinct from the Boss 429. As the cars weren’t dominant racers initially, they didn’t attract significant attention. It wasn’t until decades later, as the collector value and historical significance of Boss Mustangs soared, that interest in locating these ultra-rare Cougar counterparts resurfaced.

An original advertisement from National Dragster magazine in 1971 listing Fast Eddie Schartman's Boss 429 Cougar for sale.

Understanding the Boss 429 “Semi-Hemi” Powerplant

Ford conservatively rated the Boss 429 engine at 375 horsepower, primarily for homologation and insurance purposes. However, it’s widely believed that the engine produced power figures closer to 500 horsepower in reality. While derived from Ford’s NASCAR 429 engine program, the street version featured milder tuning but remained exceptionally potent. Its most distinguishing features were the massive aluminum cylinder heads with semi-hemispherical combustion chambers. The engine also boasted a robust bottom end with a forged steel crankshaft and connecting rods. In stock street trim, its performance was roughly comparable to the 428 Cobra Jet, which explains why “Dyno Don” opted for the more exotic 427 Cammer for outright drag racing performance. Schartman reportedly raced his Cougar only a handful of times, primarily using it for the intended purpose: conducting performance clinics.

Detailed view of the legendary Boss 429 engine, known for its large aluminum heads and performance potential.

Despite its somewhat tame factory tune, the Boss 429 engine responded exceptionally well to modifications. Simple bolt-on upgrades could unlock significant horsepower gains. Thanks to its durable forged internals, the engine could reliably handle substantial power increases, contributing to its enduring legacy among performance enthusiasts.

Why No Production Run?

Compared to the significant marketing efforts surrounding later performance models like the 2012 Boss Mustang, Ford invested minimally in promoting the original Boss 429 Mustang. Awareness was largely limited to knowledgeable enthusiasts and those actively following Ford’s racing activities. The primary motivation for producing the Boss 429 cars was NASCAR homologation – Ford needed to sell 500 units to the public to legalize the engine for competition against Chrysler’s HEMI. Although the initial target was 500 cars for 1969, demand and production realities resulted in 857 Boss 429 Mustangs being built that year, along with the two experimental Cougars. In 1970, production dropped to 499 Boss Mustangs, and no further Cougars were built.

Even with minimal advertising, Ford exceeded the homologation requirement for the Mustang, highlighting the engine’s inherent appeal. However, this focus on the Mustang meant there was never a serious plan for a production Boss 429 Cougar; the two existing examples were solely intended as promotional tools rather than potential volume models.

The Fate of Fast Eddie’s Unicorn Cougar

So, what ultimately happened to Schartman’s unique Boss 429 Cougar? In 1971, Schartman sold the car to Lou Cerra, who replaced the engine and continued to race it through 1973. It then changed hands again, purchased by Steve Comstock, who installed a formidable 454 cubic inch Holman & Moody-built Boss engine. Comstock campaigned the car for several years before the chassis reportedly suffered significant twisting due to the immense torque and lack of structural reinforcements common in modern race cars (it used a simple bolt-in roll bar kit and lacked subframe connectors). The car sat unused for some time before being acquired by Douglas Herzog, a racing engine builder and noted Boss 429 enthusiast.

Herzog embarked on a meticulous restoration of this historically significant vehicle, aiming to return it to its former glory while incorporating necessary updates to ensure its structural integrity for potential future track use. He documented the restoration process, sharing the journey of bringing this incredible piece of muscle car history back to life.

Conclusion

While the Boss 429 Mustang rightfully holds its place as a revered icon of the muscle car era, the story of the Boss 429 Cougar serves as a fascinating footnote, representing an even rarer chapter in Ford’s performance history. These two “clinic cars,” built for promotion but woven into the fabric of drag racing lore, highlight the experimental spirit and intense competition of the time. Though the Mercury brand eventually faded, the enduring legacy of unique machines like the Boss 429 Cougar continues to captivate enthusiasts, reminding us of an era when horsepower reigned supreme and incredible muscle cars prowled the streets and strips.