Fewer than 900 Boss 429 Mustangs were created for 1969, followed by a smaller run of just 500 copies for 1970, prior to the cancellation of Ford’s corporate racing program. Although the Boss 429 was conservatively rated at 375 horsepower in street trim, it easily developed over 600 horsepower in racing tune, and today, it remains one of the most exotic racing engines conceived and produced by Ford during the “Total Performance” years.
This well-documented Calypso Coral Boss 429 from 1970 carries Kar Kraft number 2272 and received a ground-up restoration by the prior owner, a collector from the Pacific Northwest. It may also be familiar to Boss 429 fans, since this very Mustang was featured in the March 1991 and July 1992 editions of Muscle Mustangs and Fast Fords. Following acquisition by the current owner in May 2001, it was sorted, and since then it has been maintained within his private collection.
As offered, the Boss 429 continues to benefit from excellent exterior paintwork and chrome, while the engine bay is highly detailed with the appropriate chalk markings and decals in place, along with the correct and oftendiscarded emissions equipment. The black interior remains beautiful and in superior condition, and highlights include an AM radio, power brakes, power steering and a Hurst shifter. A set of Magnum 500 wheels and BF Goodrich raised white-letter tires complete the package. This Boss 429 has everything an enthusiast wants: a unique and rare muscle car, stunning good looks, enormous power, and complete documentation.
SCM Analysis
Detailing
| Vehicle: | 1970 Ford Mustang Boss |
| Years Produced: | 1969-70 |
| Number Produced: | 857 in 1969; 499 in 1970 |
| Original List Price: | $4,900 |
| SCM Valuation: | $175,000-$200,000 |
| Tune Up Cost: | $500 |
| Chassis Number Location: | kk on foil decal on inside of driver's door above ford VIN/trim tag |
| Engine Number Location: | kk number on rear of engine block |
| Club Info: | Mustange Club of America 4051 Barrancas Ave. PMB 102 Pensacola, FL 32507 |
| Website: | http://www.mustang.org |
| Alternatives: | 1970-71 Plymouth Hemi Cuda, 1970-71 Dodge Challenger, 1969-70 Ford Mustang 428 SCI, 1970 Pontiac GTO Judge RA IV |
This car, Lot 131 at RM’s Classic Muscle & Modern Performance auction on June 19, 2010, sold for $156,750 including commission against a pre-sale estimate of $175,000 to $250,000.
The Mustang Boss 429 is one of the best “what ifs” of the muscle car world. For reasons unknown to most people, Ford chose the Mustang as the production car they would use to qualify their new, high-rpm, semihemi, big-as-a-house 429 engine for NASCAR.
Think about that for a second. Do you remember Mustangs running in NASCAR? I don’t. Why didn’t they shove that 429 engine into one of their bigger Fords, such as the Torino, that actually did run in NASCAR? Ford already had the 428 CJ Mustangs to compete with the Mopar Hemis and big-block GM pony cars. What’s more, the Cobra Jet engine fit the Mustang chassis like a glove—so well, in fact, it just about dominated SS drag racing when introduced in mid-1968.
So, regardless of the logic (or lack thereof), Ford decided to somehow cram the huge 429 into the Mustang. The modifications needed to do so were substantial, as everything from different shock towers and inner fenders to special suspension components were needed. This was too complex of an operation for the Mustang assembly line, so the project was farmed out to Kar Kraft, which literally built every “Boss 429” by hand.
Parts with eye-bulging prices
In the end, a Boss 429 left Kar Kraft with hundreds of unique parts compared to a regular Mustang. Everything from the lug nuts to the fenders was B9 specific, and these original parts are like gold today.
Now, all of this effort from Ford and Kar Kraft would have been forgotten had the B9 conversion actually worked as well in the real world as it did on paper. To meet emissions standards, the NASCAR-spec 429 was detuned to a mere shadow of its racing brethren. Adding insult to injury, the manifolds and exhaust installed in the cramped Mustang chassis strangled any last hopes of a 12-second monster.
When new, a perfectly tuned Boss 429 ran the quarter-mile in the high 14-second range, which means a good 428 Super Cobra Jet Mustang would pull your headlights out as it walked on by.
And, for those owners who opened up the exhaust of their B9’s with headers and good pipes—and put in a proper high-lift cam, a good carburetor, and got the engine back to 450-plus horsepower—they soon learned all of that weight over the front wheels made getting the rear wheels to hook up was a pipe dream.
Street cred remained a dream
Ford sold enough Boss 429-fortified Mustangs to get the engine cleared as a production motor by NASCAR, but they could never sell enough to earn them any street cred. Ford tried to save face by sending out a special edition of the dealer-only Ford Shop Tips magazine with Boss 429 tuning suggestions for better performance— including numbers for “hot rod” parts—but it was too little too late.
The good news is that 40-plus years later, there are plenty of gearheads that know how to make a Boss 9 work like it should have from the beginning, so most restored cars are pretty brutal performers if done right.
The difference between an elite car and a driver
As for our subject car, let’s dive into what makes some Boss 429s worth a fortune and some worth far less.
Remember those hundreds of unique parts I mentioned earlier? Well, the Boss guys sure do, and if any of them are missing from a car it is a big deal to put right. For example, N.O.S. B9 lug nuts can run you $3k a set. An N.O.S. Ford exhaust can exceed $15k. B9 shocks? If missing, I’ve seen them trade for $5k. Even the special battery in the trunk is worth a fortune, not to mention the original vent caps for the same.
I am confident if one set out to buy every unique B9 part and just lay them out on a garage floor, the expense would exceed what an average B9 can be bought for today. In short, these are one of the few cars where the car is the cheap part. It is in the bits and pieces where the true collector value lies.
The auction company’s text describes this car as a driver-level restoration with no mention of the original drivetrain. Add in photos that show some incorrect items, and this is a good, entry-level B9 for somebody that just wants one and doesn’t care about ultimate originality.
To bring a car like this to the level needed to win the super-competitive Mustang Club of America trailered concours shows would take at least $100k—perhaps more. And if the original engine and transmission are not present, that greatly reduces its value among serious Mustang collectors. Another factor is that most buyers prefer the 1969 version, even though almost twice as many were built. So, be careful when comparing 1969 and 1970 Boss 429 values.
So, was this big bad Boss Nine a bargain at over $30,000 below the low estimate? The precise answer is “it depends.” If the buyer wanted one of the wildest muscle cars ever built—in a great wild color—to drive to the Tastee Freeze every Saturday night, then yes, this result offers good value for an end user.
If the new owner bought it with intentions to make a concours champion out of it, that would be an exercise in spending too much money. In either case, as today’s Boss 429 prices are less than half of the $400,000 to $600,000 they soared to a few years ago, it is a good time to buy the undisputed King Kong of the Mustang world.
Even today, the best, 100-point concours 1970 Boss 429 is still a $250,000 to $300,000 car. So, this car at $156,000 was a market-correct price for an entry-level B9. If some of the important questions were answered, such as whether the drivetrain is original and how much “ full documentation” was available, another $20,000 on the sale price wouldn’t have been a surprise.
As presented, this car was a fair deal for both buyer and seller.