The Boss 302 Mustang was first produced in 1969 and almost immediately became an automotive legend. With its sporty looks, performance attributes, and scarcity, it was an instant hit. It continues to be highly sought after today.
Designing the Boss 302
The Boss 302 was created as part of Ford’s homologation efforts. These rules allowed Ford to certify cars to race. At the time, Ford was pursuing the strategy of “Race on Sunday, Sell on Monday.” For the Mustang at least, the strategy worked out very well.
When the Mustang first debuted, Ford asked for Carroll Shelby’s help to make it a race-ready machine. The GT350R held the B-class Sports Car Club of America (SCCA) title, and made people pay attention to the race-potential of the Mustang.
By 1969, Carroll Shelby was looking to take a break from designing cars. Ford needed a new contender for the SCCA league.
SCCA rules stated that to be eligible for the league, a production model of the car also needed to be available. To keep racing the Mustang, Ford needed to produce a new race-ready model. Fortunately, they’d already hired exactly the right person for the job.
Larry Shinoda was a noteworthy car designer for a lot of reasons. His history as a hot-rodder meant he understood performance as well as design. A gifted designer, Shinoda was responsible for several other automotive icons, including the Corvette Stingray and Boss 429 Mustang.
Bunkie Knudsen and Larry Shinoda were both recruited from GM. As GM employees, they were intimately familiar with the Camaro Z28. They knew the internal specifications of the Mustang’s top competitor. And they knew how to beat it.
Shinoda gave the Boss 302 its iconic look, its upgraded performance specs, and even its name. When asked what project he was working on, Shinoda would simply respond, “The Boss’ car.” The name stuck. Though Shinoda was just referring to Bunkie Knudsen, Boss was also popular slang at the time for something being “cool.” And there was zero doubt that the Boss 302 was cool.
The 302 portion of the name references the cubic displacement of the engine the Boss 302 used.
The Boss 302 did exactly what it needed to. It reclaimed the SCCA Trans-Am Championship from Chevrolet.
Two Boss 302s were entered in the championship race: one driven by Parnelli Jones and the other by Dan Gurney. These Boss 302s are special, as they’re the only Boss 302 Mustangs that were worked on by Shelby-American. That makes them the only Shelby Boss Mustangs in existence.
The Boss 302’s performance specifications were enough to turn heads at the time:
- 0-60 mph in 6.9 seconds
- Quarter-mile speed of 14.6 seconds (at 98 mph)
- Top speed of 118 mph
The Boss 302 Engine
The Boss 302’s engine was an especially important part of its build. Ford’s entire purpose for building the Boss 302 was creating a production vehicle that could validate their race car’s engine. So they needed an engine that could win.
The Windsor small-block V8s were tried and true, but they also had some limitations. Most notably, the cylinder heads were restrictive, blocking airflow. Though a Cleveland engine was in development, it was larger and wouldn’t work for the Boss.
So, Shinoda and his team combined the best of both worlds. The Windsor block’s cylinder heads were replaced by the less restrictive Cleveland engine heads. Thus the Boss 302 became the first Mustang to use the Cleveland heads, years before they would see regular production.
Mating the Windsor and Cleveland required a few more modifications:
- A strengthened engine block
- 8 valve cover bolts (instead of the usual 6)
- High-strength steel connecting rods
- Smaller spark plugs (made more room for the valves)
The result was phenomenal. Though the Boss 302’s official horsepower is listed at 290, most put it much higher than that. One Ford engineer, Bill Barr, dynoed the engine at 314 hp with all equipment, and 390 when stripped down. It was common for manufacturers to understate the horsepower capabilities of their engines. This was a maneuver designed to keep the insurance companies at bay.
- 4” bore x 3” stroke
- 2.23” intake valves
- 1.71” exhaust valves
- High-lift camshaft
- Forged steel crankshaft
- Holley 780 cfm 4-barrel carburetor
Boss 302 Performance Modifications
Naturally, you can’t just drop in a more powerful engine and be done with it. The Boss 302 received many additional performance modifications. Without these, the engine’s power would never have reached the pavement.
Transmission and Rear End
The Boss 302’s transmission was a standard 4-speed toploader, available in a close or wide-ratio. No automatic transmission options were offered for the Boss Mustangs.
From there, Boss 302 owners had their choice of several desirable rear gear axles. The standard was a durable 3.50 with an open differential. They could also select a 3.50 with a limited-slip differential (traction-lok), or a 3.91 limited-slip. The final rear gear option was a 4.30 with a Detroit no-spin differential. This last option was a locking differential, most appropriate for race cars.
The Boss 302 was quickly labeled “the best handling Mustang yet” by Car and Driver. It achieved this by having an exceptional suspension. Extra bracing on the shock towers, stiffer springs and shocks, and staggered rear shocks delivered improved handling.
Though an 0.85” stabilizer bar was slated to be used, it was swapped out in favor of a 0.72” front sway bar.
Manual steering and front disc brakes finished the handling adjustments. One engineer remarked that the secret to the Boss 302’s handling was minor adjustments. For the most part, it had the same suspension geometry as a standard Mustang.
Naturally, a great sound was important to drivers. New manifolds were designed to go with the Cleveland heads. A transverse muffler system helped add uniqueness to the exhaust note.
Wheels and Tires
All Boss Mustangs came with Magnum 500 chrome wheels. Superfat wide oval F60x15 bias-ply tires were chosen to accompany these wheels. The result was a widebody look. The fender arches had to be increased to provide enough clearance. Improved front spindles were also added to enhance the cornering capability.
Appearance and Exterior Features
The Boss 302 has impressive performance specs, but the first thing people notice is how sporty it looks. One of the great things about the Boss 302 is that most of its exterior modifications also serve a purpose.
The Boss 302’s hood is painted with matte black paint to eliminate glare. It also received a standard chin spoiler to help reduce aerodynamic drag. The Boss 302’s side stripe contained its name, though it served no practical purpose.
A rear wing and rear window louvers were sporty options that could be added. They came in the same anti-glare black as the hood.
1969 vs 1970 Boss 302 Mustangs
There were several small changes made between 1969 and 1970 for the Boss 302 Mustang. The only performance-related change was to the suspension. Ford added a rear sway bar, which allowed them to upgrade the front sway bar to the originally-planned 0.85” one.
You could also get an optional Shaker hood scoop for the Boss 302 in 1970.
Other than that, the changes were all aesthetics.
While the 1969 Boss 302 featured a bold “C” shaped side-decal, the 1970 version featured a hockey-stick shape. The purpose for this was simple, the stripe came up and joined the (now slimmer) hood stripe.
Color options were also significantly expanded for 1970. The 1969 Boss 302 Mustang came in Bright Yellow, Calypso Coral, Wimbledon White, or Acapulco Blue. For 1970, these options expanded to include many more colors.
Thanks to the Boss 302 registry, we now have a good estimate of how many Boss 302 Mustangs were produced in each of the available colors.
1969 Boss 302 Production by Color
1970 Boss 302 Production by Color
|Light Ivy Yellow
|Medium Lime Metallic
|Bright Gold Metallic
|Medium Blue Metallic
In the end, Ford produced 1,628 1969 Boss 302 Mustangs and 7,014 1970 Boss 302 Mustangs.
Buying a Used Boss 302
It’s difficult, and expensive, to find a used Boss 302 Mustang. Even though 8,642 were created, most were driven hard and gave up the ghost a while back. As of 2019, Hagerty evaluated a1969 Boss 302 in perfect condition as being worth $135,000. They also determined that this would be the most valuable of the Boss 302 Mustangs given its scarcity.
While $135,000 for a collectors’ car is pretty acceptable, not a lot of people have the opportunity or the cash for that kind of investment. Most people who admire the Boss 302’s performance or appearance opt to create their own via the aftermarket.
Honestly, Larry Shinoda would be ecstatic to know his work continues to inspire people to go out and add some neat things to their Mustang.
Whether you decide to drop in a full Boss 302 crate engine or just add some heavy-duty suspension components, you’ll be making a Mustang that’s a half-step closer to the Boss 302.
The Boss 302 Legacy
Unlike the Shelby Mustangs, the Boss 302 has returned only once. In 2012 and 2013, the Boss 302 returned for a limited run. Given the success of this run, it’s surprising Ford hasn’t released a new Boss Mustang.
In just two years, the Boss Mustangs created a legacy that’s guaranteed them a spot in the pony car hall of fame. These performance-oriented cars proved that a Mustang doesn’t need Shelby in its name to dominate the track.
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