Car Culture & Entertainment / News & Car Culture / Top 10 Mustangs/50th Anniversary

Top 10 Mustangs of All Time (#3): 1969 Boss 429

Image/CJ DUB, CC BY-SA 2.0 CA

 If you’re a fan of the #3 Mustang on our list of all-time greats, you can thank…Mopar???


Truth is there is plenty of credit to go around for the 1969 Boss 429 Mustang, but the impetus for the legendary “Boss 9”  was Chrysler’s 426 HEMI engine. Ford was looking to develop a hemispherical engine that could compete with the 426 Elephant, which was highly successful in NASCAR’s then Grand National Division. The end result was one of rarest and most-valued muscle cars of all time: the Boss 429 Mustang.

The 1969 Ford Mustang Boss 429 was powered by Ford’s new 429-cubic-inch engine, which featured semi-hemispherical combustion chambers. To meet NASCAR’s homologation rules, which required a minimum production run of 500 cars, Ford made just 859 Boss 429s for 1969. It’s a good thing, too, because it took a lot of doing to shoehorn the “Semi-Hemi” engine into a Mustang.

To get the massive engine—an engine that would’ve been better suited for a Torino—to fit into a smaller Ford Mustang, Ford contracted out to Kar Kraft Engineering of Dearborn, MI. The team at Kar Kraft heavily modified Ford’s existing 428 Cobra Jet and Super Cobra Jet Mach1 Mustangs to accommodate the big block. They widened the shock towers, extended out the inner fenders, chopped and displaced the motor mounts, and relocated the battery to the trunk. They also lowered the suspension, which ultimately made the Boss 429 a better-handling muscle car than many of its counterparts.

In other words, the Boss 429 was essentially hand-built.

The 1969 “Boss 9” was rated conservatively at 375 horsepower and 450 ft.-lbs. of torque, but actual output was thought to be well over 500 horsepower. Each of the rare 859 Boss 429s was given special NASCAR identification, which was placed on the driver’s side door. And in 2013, an unrestored 1969 Mustang Boss 429 sold for $417,000 at a Mecum auto auction.

That’s 417,000 more reasons the 1969 Ford Mustang Boss 429 lands in our Top 3.

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  1. I like the article…just forgot one special Mustang…’03-’04 Cobra “Terminator”, the Mustang that put the nails in GM’s pony car coffins after they ended the Camaro and Firebird. It was so beautiful at the time, I’m glad I got to watch it and own them (Terminators).

    • Andre Makina says:

      The 03-04 mustang is a ugly cheap disgusting piece of shit! You compare that to the timeless designs of the 1969? GTFO

  2. Miguel Del Rosario says:

    Hi;to who concern,In my opinion, the 1969|1970Boss 429CI was and it is and I’ll be the best all American Muscle carg of all time,by thousand of miles, no question about it,every inch of that car is like gold, and the look of the design is tremendous style,is aggressive looks is overwhelm,with his massive big engine, no even the new muscle cars can stand nest to him, you can notice the difference right away that’s all I have to say the rest is history.thanks yours truly Miguel.

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