BRAND-NEW BOSS: An impeccably restored 1970 Boss 429 Mustang heads to the Northeast Auction
May 17, 2017
Posted by Barrett-Jackson
Written by independent automotive journalist Steve Statham
This rotisserie-restored 1970 Grabber Blue Boss 429 Mustang (Lot #650) will be crossing the block at the 2017 Northeast Auction.
Not all of us were around to buy a classic 1960s American muscle car new off the showroom floor. Some of us simply weren’t big enough to reach the clutch pedal in 1970, while others hadn’t yet booked passage to life on planet Earth. But thanks to the state of today’s restoration industry, it’s entirely possible to purchase what is essentially a new/vintage muscle car. Better than new, even, if that’s your thing.
Take the 1970 Grabber Blue Boss 429 Mustang (Lot #650) that will cross the block at Barrett-Jackson’s Northeast Auction at Mohegan Sun in Connecticut, June 21-24. While the title says it’s 47 years old, you’d be hard-pressed to find a new Mustang at your local Ford dealer that’s any nicer.
Rotisserie restored and having traveled only 10 test miles since emerging from the shop, this trailered MCA Concours Boss 429 is a best-case example of Ford’s Total Performance ambitions. In MCA judging it scored 994 points out of 1,000, putting it in elite territory.
That attention to detail is crucial when shopping for a Boss 429. The Boss ’9 has long been recognized as one of the most desirable Ford muscle cars thanks to its unique pedigree. This was no mere stripe n’ scoop muscle car ‒ it was created to be the production car home for Ford’s Boss 429 racing V8 in order to qualify the engine as “stock” enough to satisfy the sanctioning bodies of the day.
The massive cylinder heads with their sculpted valve covers are the big-block’s most prominent feature. With “semi-HEMI” combustion chambers and enormous valves and ports, the free-breathing Boss 429 was more than sufficient to keep the Torinos glued to the high banks of Daytona. Like other serious high-compression racing engines, the Boss 429 V8 used a dry deck arrangement that utilized O-rings in place of cylinder head gaskets. Other beefy parts included a forged steel crankshaft and a block with four-bolt nodular iron main bearing caps.
All of the above made for a potent racing engine, but Ford had to detune the Boss 429 for the street. Camshaft and exhaust manifold choices played a part in that, as did the production car’s Holley 735 cfm four-barrel carburetor mounted on an aluminum intake manifold. Ford gave the engine a conservative factory rating of 375 horsepower and 450 ft/lbs of torque.
Because of the engine’s sheer size, Boss 429 Mustangs were not built on the Mustang regular production line. Partially assembled Mustangs set up for the 428 Cobra Jet were sent to Kar Kraft in Brighton, Michigan. Once there, the shock towers were re-engineered to allow extra clearance for the massive engine, and the front suspension was moved forward. Even after that, more room was needed, so the battery was relocated to the trunk, and a thinner brake booster was installed. Thanks to the racing nature of the engine and the special production line, the Boss 429 was Ford’s most expensive Mustang in 1970.
All 1970 Boss 429 Mustangs came with a 4-speed Toploader transmission with Hurst shifter. The rear end was a Traction-Lok differential with 3.91 gears. Also standard was a front air dam, fat rear sway bar and the big hood scoop, newly painted black for 1970.
As were required on all Boss 429s, this example has the Drag Pack, high-back vinyl bucket seats, AM radio, Rim Blow deluxe steering wheel, Convenience Group, Decor Group, console, power disc brakes, fiberglass belted tires, competition suspension, and deluxe seatbelts with warning lamps. You could forget comforts like air conditioning ‒ there simply wasn’t room in this race-minded engine compartment.
Ford only built 500 Boss 429 Mustangs in 1970 and not all of them have survived to the present day, making this car a rare treasure. This one comes with three copies of the Ford Window Sticker, Deluxe Marti Report, and MCA judging sheets ‒ in other words, as much paperwork as a new Mustang. You may have missed your opportunity the first time around, but come the Northeast Auction in June, you’ll have the chance to bring home vintage muscle that’s as close to new as you can realistically get.
For up-to-date information on this vehicle, click HERE.