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1970 FORD Mustang Boss 429- Volo PDF Print E-mail
Written by Double Dragon
Monday, 28 May 2012 17:06

1970 FORD Mustang Boss 429- Volo Auto Museum and Sales


Writing and photography copyright D. S. Brown

70 mustang boss 429 front nose

Ford got the jump on everyone April 17, 1964 with the 1965 model year Mustang which proved to be a giant hit. The Plymouth Valiant based Barracuda came out a couple of weeks earlier and provided the same ponycar concept with the added bonus of utilitarian space due to the fastback, but Ford was the one who wed the ponycar concept with the right looks. 1967 was the year Ford felt the backlash. GM struck back with the copycat 1967 Camaro and Firebird, while Mercury refined the Mustang to create the Cougar. Plymouth who had the Barracuda all along gave it a non-Valiant derived body to help combat the Mustang's good looks. AMC fielded the Javelin. Five ponycars to slice up the market chopped into the Mustang's former monopoly.


The Mustang ponycar slot became even more crowded by the end of the 1960s with the new Challenger but that's jumping ahead of things. In 1967 the top dog 390 Mustang was lacking in street credentials. Compared to the crop of musclecars out there, it was a stone. The Shelby Mustang GT-500 got the 428 and it was fast, but also a bit elite. The true musclecar was always an 'everyman' affordable package. Ford finally got it right with the 1968 1/2 428 Cobra Jet. The CJ wiped out every other factory drag car and established the Mustang as a genuine musclecar.

In 1969 the Mach 1 made a big stir, but Ford wasn't done. The former GM performance duo of Bunkie Knudsen and Larry Shinoda were hired into the Ford camp to wave their Z-28 magic wand at the 1969 Mustang. They came up with the spectacular Boss 302. The 1969 Boss 302 was not just a homologation package for the Trans Am racers. It was designed to be the best handling factory car available for sale to the public. It also had the looks to go with the performance. Well thought out stripes, spoilers and blacked out hood made a big hit on the street. The Boss was a popular 1960s slang term for something great or the best. It also made reference to Bunkie Knudsen as 'The Boss'.

The Boss 302 had the highest profile of the Boss cars, and some people only vaguely recall that the Boss name was simultaneously applied to the 1969 Boss 429. In this instance, the homologation efforts were catering to NASCAR. The Ford 429 was intended to compete with the Chrysler 426 Hemi. The 429 wasn't a true 'hemi' but it did feature crescent shaped combustion chambers earning the moniker 'Semi Hemi'. Everything was race ready: 4 bolt mains, forged steel crank, giant intake valves. The heads were aluminum as was the high riser intake manifold.


The first production 1969 Boss 429 was completed Jan 15, 1969. The external appearance of the Boss 429 car package wasn't as intense as the Boss 302. Everything was utilitarian. The hood scoop and front spoiler were functional. The fender wells were modified just like the Boss 302 to accept the great looking 15 inch Magnum 500 wheels. The front wheels also sat on a wider lower track in the case of the 429, making it a better handler than a 428 Cobra Jet.

Ford probably figured the small 429 stickers on the front fenders were sufficient for those in the know. Extrapolating from the fact that the factory didn't have the time to deal with making the 429 fit into a Mustang, we may surmise that time and energy may have also been a factor in the subdued appearance of the Boss 429s. Ford just wanted to get approval for the 429 engine in time for the races and didn't have anything left for the street cars.

Of course we're using the term "subdued" in the context of the times. 1969 muscle cars saw the Judge and lift off hood Roadrunner Six Pak leading a parade of some of the wildest in your face creations ever seen out of a factory door. Just three years earlier in 1966, the Boss 429 would have been an extreme visual statement. Options abounded in the Ford bins at the time and many availed themselves of these add-ons, including our feature car.

The OOCC Mustang Boss 429 packs some extra wow factor with the optional sport slats mounted on the back window. The optional rear spoiler looks so 'right' that it's hard to envision this car without it.


Ford farmed the 429 out to Kar Kraft in Brighton, Michigan to transform 428 Cobra Jet Mustangs into Boss 429s. One cubic inch of displacement doesn't sound like much, but the 429 had huge external dimensions and massive valve covers on the same scale as the Chrysler Hemi.

Front suspension had to be moved outwards using unique spindles and control arms. The Boss 429 was lowered to improve handling. Inner fenders were widened, and shock towers moved outwards. The battery was put in the trunk and a sway bar was added to the rear of the car. That was all just to get the engine into the car and have it still steer.

Kar Kraft also created the hood scoop by cutting a hole in the hood. The outer fender metal was rolled out of the way just like on the Boss 302 so that the bigger 15 inch wheels and F60x15 Goodyear Polyglass tires fit. Dual racing mirrors were part of the package as well as the oil cooler.

The 429 was factory underrated at 375 HP. Experts assert that the 429 was somewhere in the 500 HP neighborhood. This awesome potential straddled a wide chasm on the way to street reality. The best quarter mile time CAR LIFE got from a 1969 Boss 429 was 14.09 at 102.8 MPH. This is fast, but the 428 CJ could equal these numbers all day long. HOT ROD got a CJ into the 13s. Top speed of the CAR LIFE 429 was only 118 MPH with the 3.91:1 rear end, which seems odd. Chrysler Hemi cars with similar axles had tremendous top speeds as a simple byproduct of the enormous horsepower defying wind resistance pushing against boxy 1960s shaped cars.

Supposedly, headers, cam and a good tune-up unleashed the true potential lurking within the 429 engine. The main problem on the street was simply that this was a high revving race engine not a low end torque streetlight terror.

A good friend of mine ran into a similar problem with a monster 455 engine he built for a Trans Am. He ignored the engine builders and insisted on insane carburetors and a full on race cam. The car shook the windows of every house for two blocks and would stall if you didn't stay on the gas pedal. Low speed driving was virtually impossible. The car was moderately quick until 80 MPH and then it started to bite into the road. He had to rebuild it with a street cam. Detuning of the 429 still wouldn't address the massive ports and intake design, giving a similar absence of low end responsiveness.

In 1970, the 429 theoretically would be even more potent because the 429 changed sometime in the middle of 1969 to a mechanical lifter cam in place of the hydraulic cam. The exhaust was improved for 1970 which is an area that yielded results for street nuts working on the 1969. In 1970 the hood scoop was painted black likely as a nod to the Boss 302's flat black painted hood.

Despite its giant potential, the Boss 429 didn't build up a street rep. It came at a time when every manufacturer had supercars out there with well over 400 cubes combined with wild graphics. The muscle car legends of 1970 were specifically built around street acceleration. The LS-6 Chevelle, the GSX, the Hemi Cudas, L88 Vettes and 428 Mach 1 legends persist because these cars were tailored to stoplight and quarter mile competition.

The Boss 429 was a flat out racer which didn't fit into the muscle car formula. The Boss 302 suffered lack of off line snap, too which kept it out of the mainstream of 1970 muscle. The Boss 302 had an image and handling which translated to street credentials within the special niche occupied by the LT1 Vettes and Z-28s.

There really wasn't a big following for the street versions of the oval racers. Where do you drive a car at a sustained high speed? All the street action happened from stoplight to stoplight. That is where the reputations were created. The winged warriors from Mopar were notoriously hard to sell and not just because of their outrageous appearance. Even restrained tie in cars like the Charger 500 or the Mercury Spoilers didn't make a big splash on the street. The simple reason is that muscle cars made their street reps twenty times a day at stoplights and only the big block straight line acceleration supercars made the cut.

The lack of identity at the time followed the Boss 429 down through the years. Collectors did preserve them out of historical interest, but without street mojo the values didn't exaggerate like Hemis and LS6 cars did. The Boss 429 was tailor made for collectors when you look back at it. Special tie in to a racing event, rare exotic engines and good documentation. Each Boss 429 received a Kar Kraft number which supplemented the factory VIN. Below the OOCC Boss 429 tag reads "KK 429 NASCAR 2462".


The Marti Auto Works Report on the OOCC Boss 429 indicates assembly five days ahead of schedule in the Dearborn, Michigan factory December 3, 1969. Below the invoice is date stamped Dec 10, 1969 for the date of release from the factory. The Marti Auto Works Report states that the car was paid for by the car dealership on Dec 9, 1969.


The Calypso Coral Boss 429 was very expensive. To start with, the 429 engine option cost the customer $1,208.00 ($955.64 dealer cost). The four speed close ratio cost $155.00 and the Drag Pack with 3.91 Traction-Loc axle was $155.00. A host of other options seen on the invoice above created $2,162.00 worth of options. The options come close to doubling the cost of the base 1970 Sportsroof Mustang itself which was a mere $2,872.00!

An interesting detail: the invoice states the car was shipped with 4 gallons of gasoline. Usually the 'as shipped' weight includes a token amount of gas, often less than 3 gallons. When you ship out as many cars as Ford does, low shipping weight adds savings to your freight cost. Ford provided more gas for the Boss 429 since these cars were destined for Kar Kraft and would be moved around a bit more than the typical new car. Curb weight would include about 113 more pounds once the Mustang's 22 gallon tank was filled to capacity.


The build sheet above has some interesting gaps. There is no tag number for the engine, fan, air cleaner, drive belts etc, because the Dearborn factory didn't have the 429 engines on the premises. The engines were built in the Lima, Ohio engine plant and shipped separately to Kar Kraft.

Once Kar Kraft had worked their magic, the Boss 429 was shipped out to the Jim Aikey Ford Inc. car dealership on 750 E Northwest Highway, Des Plaines, Illinois. Jim Aikey Ford Inc. was a well known high performance car dealer who usually had several new and used Shelby Mustangs on the premises. Jim Aikey Ford raised their profile even further by stocking the exotic barely disguised homologation specials like the OOCC Boss 429 and also the Torino Talladegas. See a story on this dealer under ILLINOIS DEALERS in the DEALERSHIPS section of this website.

The OOCC Boss 429 was bought from Jim Aikey Ford Inc. but not registered to an individual. The owner of Gem Top Distributors registered the Boss 429 in his company name and used it as his personal car. He removed the smog equipment but had the foresight to save it. It remains with the car but hasn't been re-installed. The interior and driver's seat are still pristine.


The original owner had the driver's door repainted at some point in his ownership. It is theorized that the door was hit, but it could have been a nick or scratch. You can see that the door panel fits properly. The door panel also shows no wear on the driver pull.


Aside from the smog equipment and battery change, the 429 was left intact. The only problem with the Boss is the clutch pedal rubber pad which is with the car but tends to fall off the base metal pedal. It doesn't take too many hard launches in a major muscle car to put serious wear on a clutch pedal. Take a look at the wear on the clutch pedal on David Dodd's all original 1968 Chevelle SS 396-375 HP 20,000 mile original in the ONE OWNER stories. The entire car is pristine, except for the clutch pad which shows hard wear on the left side.


The Boss 429 was driven minimally by the original owner. In 1998, the original owner traded in his 8,000 mile Boss when he sold his Gem Top business to use the money to buy a farm. Incredibly he relinquished his Boss after 28 years because he needed a truck for the farm. The one owner collector car status of this rare Boss wasn't of major concern to the original owner who thought of practical needs at trade in time. He traded the Boss 429 into Lyons- Ryan Ford at 104 W Route 173 in Antioch, Illinois for a Ford Super Duty pickup truck.

At the time, the truck was listed for $38,000.00. Depreciation has taken that Ford Super Duty down to the point where it holds little value. But it served the former Gem Top owner's needs, so for him the deal was a sound one. The Boss 429s meanwhile are soaring into the stratosphere of collector prices. For years they were off to the side, nearly forgotten but now collectors are getting the bug for the 429s.

Kevin Lyons, the owner of the Lyons- Ryan Ford car dealership was astounded to discover that this original Boss had nothing changed since new except a battery and the smog equipment which was in the trunk. He appreciated this car and kept it aside. The car remains frozen at 8,000 miles to this day. It is now on consignment at Volo Auto Museum and Sales.


Last Updated ( Saturday, 22 August 2020 21:00 )