Muscle Car Of The Week Episode  #123: 1969 Ford Mustang Boss 429

No bad puns or one-liners this time because the Boss doesn't mess around. This is one of the most mythical Mustangs of all time. The engine, transmission, and rear-end, and suspension systems have all been selected specifically to do one thing, and that's win races. You don't have to be a Mustang fan to agree that the Boss 429 is a super bad car. It is understated in its appearance, doesn't have crazy stripes, doesn't have a big wing on the back, doesn't have louvers over the rear window and stripes up the side. All it has is a solid color, menacing stance, some Magnum 500 wheels. In this case, they're shod with Goodyear polyglass GT tires. And it does have what is perhaps the largest hood scoop ever installed on a Mustang or most muscle cars for that standpoint. But what it does have is the biggest engine Ford ever put in a Mustang. It's the Boss 429, 429 cubic inches that are designed to go fast and move a lot of air. And what's interesting about this car is the story on how this whole thing came about. The Boss 429 really only had one mission as an engine. It was designed and built to run harder and faster and longer than the Chrysler Hemi's on the NASCAR super speedway. And the rulebook said to make an engine competitive and legal in NASCAR, they had to sell some to the general public. They chose to do that in the Mustang. However, the Mustang was not a NASCAR race car, the Torino Talladega was. So it's interesting that they legalized this engine in a different car and then raced it in the Talladega. And the Chrysler 426 Hemi with the hemispherical combustion chambers was already pushing Dodge Chargers in NASCAR races to record speeds. And Ford wanted a piece of that action, so they came up with the Boss 429. And this is basically an FE series bottom end, bored out and stroked to 429 cubic inches. But it's wearing a very special set of aluminum semi-hemispherical cylinder heads. They weren't a true Hemi, Ford actually called them a crescent shape, but a rounded combustion chamber that was designed to move a lot of air. And the rumor is that the exhaust ports are so big that somebody equated them to being similar to a shotgun blast. So that's how this engine got its nickname of the shotgun Hemi. So you'll notice we've been talking about NASCAR, but in the terms of a Mustang. So somebody made the decision along the way to say, hey, we're going to make this engine legal for NASCAR. But in the process, we're going to build the baddest Mustang ever. And to get this massive shotgun motor under the hood of a Mustang took quite a bit of work. Ford subcontracted a shop called Car Craft to actually build these cars. They sent them basic Mustang sports roof cars in which they gutted the whole front suspension and ripped the shock towers out and modified the whole front end to accommodate this giantly wide Boss 429. And once the engine was in there, they realized that there was no room for very many accessories. So you couldn't get air conditioning, for example. They shrunk the power brake booster so you could have power brakes. And they made a bunch of other chassis improvements. The car sat a little bit lower. They added a rear sway bar because it was kind of nose heavy now with this big motor in it. But if you look a little bit closer, you'll notice that it came with a smog pump to help the emissions. Well, that robs power. It also came with a relatively small camshaft considering the airflow capabilities of these cylinder heads. And what's that on top of the intake manifold is a small 735 CFM Holley carburetor. And that's rated far below the 780 CFM carb that was on top of the Boss 302. But the 429 is 127 cubic inches bigger. Plus it had those mammoth cylinder heads. So the question is, did Ford put low performance parts on these things to sell them to the public to try and keep the insurance premiums down? I think we should also point out that the Boss 429 Mustang was not the fastest thing on the street when they first came out. And you'd think with all this cubic inches and power and high flow heads and all that jazz that these things would be rocket ships. But in reality, a regular Cobra Jet Mustang would oftentimes beat these things in the quarter mile. You had to change a few things to really make these things scream. One of them was put a bigger carburetor on it. Number two, give it a little more compression. Number three, lose the street friendly hydraulic camshaft in favor of a more radical solid cam. Another factor is that Ford had what was called a product acceptability standard, which mandated that all the Ford cars had to perform certain basic functions on the street. They had to start when they were hot or cold. They had to idle in traffic. They had to run smoothly at various engine RPM and various speeds, because basically they're setting a standard for cars like the Lincoln Continental and the smooth running Ford Torinos. And to expect that a full on race motor like a Boss 429 be subject to the same, what we call noise vibration and harshness standards today, seems a little bit ridiculous and undoubtedly hampered the power of these cars. Chrysler and General Motors didn't put these kind of ridiculous limitations on their high performance engines, so they built them nastier and they vibrated and shook more, but they made more power. But at the end of the day, it's hard to argue that the Boss 9 is not the baddest Mustang ever built. Sure, there are cars today that have come out with superchargers and Shelby versions that made more power, but the evidence is when you watch a Boss 9 cross an auction block, these things get stratospheric numbers because everybody loves these cars. So that's why we chose this one to be the Muscle Car of the Week from the Brothers Collection. These Boss 429 Mustangs are truly the stuff of dreams, and sometimes it's hard for me to believe that they let me stand next to all these awesome cars from the Brothers Collection, but that's how we get to share them with you. What's your dream car? Post it up on our Facebook page or in our MuscleCarOfTheWeek.com forum. Who knows, if we have one here in the collection, maybe we'll do a video on it just for you. And subscribe to the YouTube channel so you don't miss that episode or any episode of Muscle Car of the Week.