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Get Ultimate Performance the Boss 351 Mustang Way

Get Ultimate Performance the Boss 351 Mustang Way

What’s more challenging than creating a true automotive legend? Recreating it. Automotive engineers strive to find that winning formula of performance, style and desirability that earns their car a place in the history books. The original 1964.5 Mustang is one of these vehicles. It was a smashing success right out of the gate, so you can imagine how daunting it was when Ford engineers were given the task of creating a higher-performance Mustang for 1969.

They tackled the challenge with a new 302 V8 engine. They built and installed it in the revamped 1969 Mustang, and the Boss 302 was born. A racing and commercial success, the Boss 302 would only last for two years. Ford also created another racing model, which was built simultaneously with the 302, the Boss 429. As if that wasn’t challenging enough, Ford would once again put their design team to the test with the third-generation Boss: the Boss 351. For many Mustang enthusiasts, this is the ultimate Boss and perhaps the ultimate Mustang. 

An Impressive History

Modern automotive enthusiasts can easily identify the cars that have proven themselves as leaders in the industry. The most sought-after cars combine high-performance, impressive racing feats and low production numbers.

On the other hand, there are just a handful of cars that were able to prove their importance right from the start. One of these was the Boss 351. If it were an Italian sports car, it would have automatically had a better chance of gaining an enthusiastic following. As a Mustang, however, it wasn’t a sure bet. Yet by the time the ‘Boss’ team was finished with their third Boss model, there was no doubt they had something special on their hands.

The 351 cubic centimeter (5.8L) V8 engine started life as Ford’s ‘Cleveland’ engine, but in true Boss fashion, it was heavily modified for use in the Mustang. Smaller in size and displacement than the 429 it replaced, it still managed to put out otherworldly power. The small-block V8 was known to have embarrassed more than a few big-block competitors from the era.

The previous Boss Mustangs also had potent engines, so what made the Boss 351 ’Stangs stand out from the others? The answer is precision. The attention to the rest of the details made it a better all-around car that drove as beautifully on the street as it did on the track.

A Racecar That Wasn’t Just for Racing

After pulling out of factory-sponsored motorsport racing in 1970, some performance fans were worried that the Boss would lose its focus. The 351 wouldn’t benefit from the SCCA and NASCAR racing series to test and prove them out. But that didn’t mean the Boss 351 was any less a high-performance racing machine.

Engineers were able to strike a better balance between racecar performance and everyday driving, adding some features so it could also be driven on the street. These features didn’t mean the car lost its power. In fact, the high-performing engine and suspension tuned for handling — not necessarily comfort — proved the 1971 Boss 351 could still lead the pack. 

The Most Noteworthy Features

boss351 mustang specifications

The most important feature of the Boss 351 Mustang is right in the name: the 351 V8 engine. More compact than the 429 V8 of the previous Boss, it carried some impressive high-output features and specifications:

  • 330 horsepower at 5400 rpm
  • 370 lb-feet of torque at 4000 rpm
  • 750 cubic feet per minute 4-barrel ‘Autolite’ carburetor
  • 4-bolt main bearing block
  • Solid lifters operated by a mechanical cam
  • High 11.0:1 compression ratio

Many enthusiasts at the time suspected that the engine was underrated by Ford. Testing confirmed this, showing it developed more than the advertised power. It’s no wonder the 351 was hailed as the high-performance engine worthy of being bolted into a Boss Mustang.

There’s Exclusive — and Then There’s 351 Exclusive

Back in the 1960s and 1970s, automakers typically made noticeable and significant changes to their cars every model year or two. That’s why special, limited edition models such as the Boss Mustangs weren’t uncommon. Compare that to today — the same body style and engine options are often used for five-plus years. It’s easy to understand why so many classic cars are extremely collectible today. But the Boss 351 Mustang is in a class of its own: With a production run of one single year and only 1,806 examples built, it is a rare and hard-to-find car today.

Thankfully, the appeal of these ’Stangs was recognized the day it was released and continues to this day. The automotive community makes sure the Boss 351s that exist today are respected and treated as the legends they are. CJ Pony Parts is proud to play a part in the Boss 351 story by offering the parts, accessories and more.

Finding Boss 351 Parts

351 boss mustang decal

If you want to purchase a relatively rare animal like a Boss Mustang, you need to consider the availability of parts. It’s one thing to be lucky enough to stumble across a rare find, but even a 40-plus-year-old Mustang that has been well cared for is going to need parts and repairs at some point. In the case of a specific model like the Boss 351, the task of finding parts for repairs, replacements or upgrades can be a challenging task.

CJ Pony Parts offers a comprehensive lineup of parts that are designed with 351 in mind, such as larger displacement crate engines that use the 351 block! Check out our collection of engine-related components:

  • Engines — crate engines, racing engines and blocks
  • Engine parts — cylinder heads, gaskets, crankshafts, etc.
  • Engine dress-up — valve covers, trim kits, reservoir caps, etc.

Whether you’re doing a complete rebuild, replacing damaged parts or simply performing some routine maintenance on your 351, you’ll find a solid selection of options in our online store.

The Rest of the Package

While the engine is key, its new body style is also important. This slanted-back body style, called SportsRoof, was also used on the Mach 1 model that appeared in 1971. The 60-degree angle of the rear of the car gives it an easily identifiable distinctive look and silhouette. The Boss 351 also added a few small touches that enthusiasts use to differentiate the 351 from other SportsRoof models. These intricate details include:

  • Black or argent RamAir hood with twist-lock hold downs
  • Color-keyed moldings on the hood and fenders
  • Large stripes running down the sides
  • Unique ‘Boss 351’ decals along the fenders and on the trunk lid
  • Honeycomb grille and front chin spoiler

The wild look of the SportsRoof Mustangs made them stand out from the crowd, but it takes a keen eye to pick out a Boss 351. The Boss was never meant to be the flashiest car out there — it was designed to impress when the driver turned the key and blipped the throttle.

Customization Options

When designing the Boss 351 Mustang, Ford listened to complaints about the previous models. The interiors in previous models never offered a lot of options. While the standard interior in the ’71 Boss was pretty much the same as the regular Mustang, except for the addition of an instrumentation gauge package, Ford offered all of the available Mustang interiors as optional equipment on the Boss. This allowed buyers to customize their 351 straight from the factory, making it a more enjoyable cruising car.

CJ Pony Parts has continued this customizable tradition by adding dozens of parts and accessories to our selection, so you can upgrade or personalize your Mustang. You may be one of the lucky few with an original 351, and in that case, we can help you keep your ride like new. Maybe there are some 351-specific features and parts that you want to add to your Mustang of a different model. You can pick and choose the exact performance parts and upgrades to create a 351-inspired race machine.

Finding what you need is easy at CJ Pony Parts. Everything is organized by year and model, and there are pictures and descriptions so you know you’re choosing the right part. While a ‘homemade’ Boss 351 is never going to have the market appeal of a true original, it’s possible to build your own Boss-inspired Mustang that meets or exceeds the performance of the original.

Boss 351 Final Touches

There’s a lot more that goes into a true sports car than simply the engine and the body. The engineering team on the third Boss project managed all of the details. They used what they had learned on the two previous models and the racing experience of those cars. They focused on:

  • Transmission — All Boss 351s for 1971 featured a four-speed, wide-ratio manual transmission with Hurst linkage and shifter.
  • Tires and brakes — The model included sticky, low-profile F60-15 tires and power-operated disc brakes on the front with 11.3 inch rotors.
  • Suspension — Lower than base Mustangs, the competition suspension had stiff spring rates and staggered rear shocks.
  • Rear-end — The Boss 351 came with a ‘Traction-Lok’ rear end differential, using a 3.91:1 ratio.

Other touches, such as a higher-capacity radiator, dual exhaust and a heavy-duty battery, completed the transformation from a standard Mustang to a true performance pony car.

The End Resultsuspension on 351 mustang

Speed. Handling. Ride. These are the three criteria by which sports cars are measured. The Boss 351 easily ticked the first two boxes, but other 1971 reviewers were less forgiving of the competition suspension.

Many felt that the stiff suspension spring rates were simply too stiff, and the improvement in handling didn’t justify the punishing ride. Over rough roads, the suspension bottomed out more easily than previous performance Mustangs. With the factory suspension tuning being an exception, the new Boss was considered more livable off the track.

As with all other areas of your Boss 351, CJ Pony Parts can help you with the suspension. If you agree that the factory settings need improved, why not shop our online store? We have the parts you need to get the exact balance of ride and handling that your Boss deserves. You’ll find suspension kits, shocks and struts, along with carry sway bars, subframe connectors and the necessary hardware to do a full overhaul of your entire suspension.

If you’re perfectly happy with the way the Boss 351 suspension rolled off the assembly line in 1971, we can help you keep it that way. You’ll find all of the suspension parts necessary to maintain it.

The Downsides

While it’s true that the Boss 351 Mustangs were well received and are highly regarded today, they weren’t without their faults. One of the major problems was the size. Ford had increased almost every dimension of the Mustang for 1971 except for the height — many purists found that the Mustang had gotten away from its original compact pony car ideal.

Despite the extra size, the interior felt tight, and outwards visibility was poor. This was worse on the SportsRoof models, including the Boss 351, because of the nearly horizontal rear deck. The car was larger than before, and it felt even larger than it actually was.

The extra size also brought extra weight. The high-output 351 V8 more than compensated for the extra 100 pounds of weight the 1971 Mustang carried, but in ultimate performance circles, added weight is never desirable.

Keeping a Boss 351 Alive

Thanks to the rarity and appeal of Boss cars, many that are still around today are well maintained. Unfortunately, even a prized Boss 351 will eventually show signs of age and wear. Thankfully, parts that can rust and get damaged, such as quarter panels, doors and drip rail moldings, are all available at CJ Pony Parts.

We also offer brake, cooling, wiring and interior parts, along with accessories and hardware. In many cases, we offer original equivalent parts and various upgrade options. There are far too many parts to list here — browse our full selection.

One of the Last True Muscle Cars

The 1970s marked a sad era for performance cars. A perfect storm of increased emissions, safety requirements and increasing gas prices was brewing, which meant that the small, light, high-power cars were becoming more difficult for manufacturers to build. The difficulties stemmed from:

  • Emissions — Stricter tailpipe emissions restrictions meant that high-horsepower engines were throttled, and V8 engines gave way to smaller 6-cylinder engines in many compact and midsize cars.
  • Safety — While added safety was a plus, this meant increasing size and weight for better crashworthiness in the ’70s.
  • Gas prices — Many families could no longer justify gas-guzzling performance cars, opting instead for more economical models and engines.

Did customers turn away from performance cars, causing manufacturers to remove them from their lineups? Or did the performance of these cars become less appealing, causing customers to flee? Whether it was one or the other, or a combination of the two factors, the Boss 351 Mustang became one of the last true muscle cars.

Ford wasn’t alone in seeing a drop in interest in their performance models, and the Mustang’s competition also fielded significantly less impressive pony cars during the 1970s. As one of the last true muscle cars, the performance of the top dog Mustang speaks for itself:

351 details

  • A 0-60 mph time of 5.8 seconds
  • A top speed of 117 mph
  • A ¼ mile time of 13.9 seconds at 102 mph

This is why the Boss deserves to be celebrated. It was a last hurrah for the first generation of the mighty Mustang, and it was every bit the racecar as the two previous Boss models. While the performance of the 351 was apparent and respected from the beginning, the car managed to fly under the radar and almost seemed to be forgotten as time went on. It wasn’t until several decades later that the collectors market would start paying attention to the Boss 351 in the same way it viewed the Boss 302 and Boss 429 models. From that point forward, attention and prices skyrocketed.

If you’re interested in finding an original Boss 351, getting your hands on one is a tricky affair. If you do manage to find one, you can be sure that other enthusiasts have their eye on it, too. This means there are premium prices attached to any Boss 351 Mustang that crosses the auction block.

A Place in History

A worldwide registry of Boss 351 Mustangs shows that fewer than 600 of the original 1,806 cars produced are present and accounted for. While the existing cars are well maintained, that number can only decrease over time. The appeal and community behind this special Mustang model have guaranteed that it will never disappear.

CJ Pony Parts is constantly working with quality aftermarket suppliers to make sure the steady stream of Boss 351-specific parts and accessories keep flowing. Check back often, as we are constantly adding to our parts lists. You never know when new 351 components will appear.

An original Boss is obviously the most desirable, but it’s exciting to watch other enthusiasts buy into the Boss legend, keeping it alive with their own project. Compared to a Boss, it’s relatively easy to find a SportRoof ’Stang from the early ’70s. These make excellent starting points for a 351 project. Remodeling a SportRoof Mustang also gives you more creative freedom since making modifications to an original Boss would significantly lower its value. While you’re waiting for your chance to buy one of those originals, have fun building a Boss 351 exactly the way you want it.

Will Ford once again resurrect the Boss name for a high-performance Mustang model now that the all-new 6th generation Mustang is out? If they do, Boss fans will be watching closely to see if a new model meets the same high performance and attention to detail that the originals had. One thing is for sure: Topping the Boss 351 Mustang will be a difficult task!

It’s Easy to Be Passionate About a Boss 351

At CJ Pony Parts, we provide the same excellent service whether you’re buying floor mats or a crate motor. We have competitive prices and fast shipping, as well as free delivery on most orders. We’re also passionate car fans, and we can’t help but get excited when someone asks about a special model like the 1971 Boss 351 Mustang. That’s why we encourage you to browse our online selection today and let us know how we can help. Our team is available to answer any questions, and we’ll help you make the best choice for your project.

No matter the year or model, we’re your Mustang aftermarket source. We’ll help you find the Boss 351 parts, upgrades, accessories, hardware and tools you need. Take a look at the Boss 351-specific badges, decals and stripes that give the Boss its unique look. Choose the valve cover style that looks best under your hood. Chrome? Aluminum? Flat black? We have the style you need to personalize your car.

It’s easy to get hooked on the performance legend that is the Boss 351 Mustang. From the high-output engine to the racy looks and high-performance details, there’s a lot to like about the 351. Do your part in keeping the legend of the 351 alive by joining one of the most exclusive Mustang enthusiast communities on the web. Sign up for our email newsletters today! 


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