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1970 Mid-Engine Mach I Mustang
How Building a 1969 Camaro Inspired This 1970 Mach I
Bobby Johnson built this mid-engine 1970 Mach I Mustang after the reaction he got from his previous build, a 1969 Camaro. He thought the complexity and quality of his red Camaro would draw accolades and attaboys. But before all of you Ford lovers pipe up with sarcastic comments, be aware that his Camaro was radical—with late-model Corvette Z06 driveline and suspension. It was essentially a Z06 Corvette hiding under a 1969 Camaro. Says Johnson, “It was way more difficult than this Mustang.” He included all of the features of the then-new Corvette like mega-adjustable heated and cooled seats, all of the original electronics, and a lot more. “It took me four months just to wire the thing,” he says.
But the sad part for Johnson, and the reason he took the approach he did with this Mustang, was that for as absolutely stellar as the Camaro was, it looked like just another red 1969 Camaro. “A guy would have to look real hard to even begin to see how involved it was, most everyone just passed it by,” Johnson says. If he’s building an incomparable shrine to the Chevy brethren, said brothers should at least take notice—right? He needed an adrenaline shot to the heartbeat of America. He wants his passion for building unique, exciting cars to stand out.
Johnson likes to build those “different” cars in his 8,000–square-foot shop at his house in Georgia—that is, when he’s not working all day running his paint and body shop. “I work 14-hour days, starting in the body shop and then coming home to work on a project,” he says. “My wife and daughter are into horses, while building a car every 15 to 18 months is what I like to do, so the whole family has their own extracurricular activities.” A busy family is a blissful family.
Bobby’s Mach I started coming together in his head about the time his Camaro was evaporating into the crowd, around 2006. “I bought the drivetrain out of a wrecked 2006 Ford GT and was looking for a car to put it into.” Going mid-engine with the 5.4L supercharged V8 and six-speed manual sure was different, but obviously required a radical reworking of the 1970 Mustang.
“This was a real nice, original car—in fact, I used to change the oil for the owner when I was 16,” Johnson says. An older gentleman had owned it for decades, but when he became ill he offered to sell it to Johnson, and that’s when combining the GT driveline and Mustang coalesced. To some, cutting up a nice 1970 Mach I is like the Texas Chainsaw Massacre—with sheetmetal—but Johnson is pragmatic about it. “When you start with a nice car, you end up with a nicer car.” And he does virtually all of the work himself, so it saves him time from having to put aftermarket panels onto it. And Johnson’s most compelling reason? “Rust makes me tired just looking at it.”
Johnson built a jig for the car onto a surface plate in his shop to hold the drivetrain and C6 Corvette front suspension, and then built a new square-tube frame around those components. He wanted to retain as much of the original look of a 1970 Mach I as possible, but with a functional 1969 quarter-panel vent and a lift-up hatch to reveal its hidden, mid-engine magnificence nesting inside. The only concession he made was adding 2 inches to the wheelbase at the rear to give him a little more legroom up front for what would now be a two-seater. “I drive my cars, and I wanted to be comfortable in long-distance situations,” he says. That part, he nailed. With more than 6,000 miles on the ticker, he says it drives fantastically, is comfortable for his 6-foot, 4-inch frame, and he is easily able to drive Power Tour–type 400- to 500-mile daily hauls. In fact, we first noticed the car at our 2015 ’Tour.
Once he built the frame, he added a rollcage and then placed the Mustang’s shell over the fabricated chassis. And we do mean shell. To mate the body to the newly fabbed frame, he first cut out the entire floor and cowl. From there, he welded the body to the structure and then filled in the floor and cowl panels, as well as creating a bulkhead behind the front seats to isolate the engine. He kept the bottom of the body relatively flat, in keeping with the race-car-type construction of the chassis.
Though Johnson was able to use carbon-fiber pieces throughout the car, the majority of what looks to be carbon fiber are actually aluminum sheets dipped into the hydrographic vat to replicate carbon fiber. He created a driveshaft tunnel that mimics what a front-engine car has, but instead of a spinning driveshaft, he packaged the hoses leading from the standard location Avco aluminum radiator to the engine out back. He also snaked some electrical lines through it as well.
He built out the suspension from the Ford GT’s transaxle using C6 Corvette hubs with axles fabbed to slightly narrow the track width from a stock GT, so as to fit within the Mustang’s narrower footprint. Up front Johnson incorporated a Stiletto aftermarket rack-and-pinion that steers C6 Corvette spindles on C6 A-arms, also with a narrower track width than a production C6. Phat Racing coilovers were used front and rear, as were Wilwood 14½-inch discs and six-piston calipers. The Evod one-off wheels are 18x10s up front and 18x12s in the rear, from a design by Eric Brockmeyer resembling Cobra and McLaren wheels from the 1960s. Bridgestone tires are 235/35R20 in front and 345/40R20 out back.
Johnson says for better brake feel he uses electric hydroboost on all of his builds because it works so well, and the one used for his Mach I was scavenged from a 2003 Mustang Cobra.
Once the new front and rear bulkheads were made, Johnson adapted a 2000 Mustang dash inside and used Spearco seats that copy the original 1970 Mustang pattern, stitched by Sammey Freeman. The rest of the interior is stock, including the door panels, headliner, and miscellaneous pieces.
One of the easier modifications was creating the hatch. Johnson welded in the rain channels and machined the hinges. Gas shocks aid opening and closing. Because of the way the rear of the top is constructed, it lent itself to this seemingly difficult modification. Says Johnson, “It’s fun listening to ‘experts’ tell their friends how rare the hatchback option was.” For the record, there was no hatchback Mustang from its inception in 1964 up to 1974, when the Mustang II debuted the feature.
Once the Mustang was back together, Johnson performed the minor bodywork that was necessary to hide some of the changes he made and then painted the entire car in PPG 2008 Shelby Mustang yellow. Johnson says he uses PPG products exclusively at his shop and on his own personal projects.
The larger wheels and lower stance help to hide the 2-inch wheelbase extension, and without the hatch up, it’s hard to know what has just pulled up next to you at a stoplight—but you know better than to try a speed contest just from the sound it makes idling.
This isn’t the first 1969–1970 Mustang with a mid-engine conversion HOT ROD has featured. Both Johnson’s 1970 and Terry Lipscomb’s 1969 were started and completed at the same time and were mutually exclusive, so neither builder knew of the other’s similar state of mid-engine mindset. And both are completely different in terms of their overall approach to the mid-engine madness.
At the 50th anniversary of the Mustang in Charlotte, Johnson’s Mach I was chosen as one of the top 10 Mustangs of the event, and it has also won its fair share of trophies at other events Johnson has attended.
Concludes Johnson, “Every time anyone builds a car, he wants to do something different or better than the previous build—it’s just human nature.” This car is a byproduct of that mindset.
How Rare Is a 1970 Mach I?
Total 1970 Mustang production was 190,727 units, of which a tad more than 20 percent were 63C Mach Is. All were Sportsroof or fastback body styles—none of the 40,970 units made came in coupe or convertible versions. Engine options spanned from the 351 Windsor two-barrel engines, up to the “drag pack” 428ci Super Cobra Jet engine.