Leading the pony car field through the 1960s, the Ford Mustang would see its third generation debut in 1969. Available in seven models and ranging from a coupe to a convertible to the sporty fastback, Mustang was at the top of the most wanted list.
By 1970, Mustang had evolved into not only a sporty street cruiser, but also an accomplished road racer, a Trans Am circuit champion and a drag-strip terror. The special-order Boss 429 produced by Ford sub-contractor Kar Kraft was a limited-production car developed to allow the new Boss 429 engine to qualify for NASCAR racing. Mustang had made its mark in virtually every racing venue it qualified for and continued to uphold the “win on Sunday, sell on Monday” sales mantra. While the market had become almost saturated with pony cars, Mustang still managed to capture the top sales spot, selling 190,727 in 1970.
For Mark Gawthrop of Stony Mountain, performance is front and centre.
As the owner of Corners Quickly from 1988 to 2008 he’s racked up more than two decades of building street performance and racing engines.
Gawthrop’s 1970 Mustang Mach I is a local Winnipeg car purchased new from Dominion Motors. After seeing a couple of years on the street, it ended up being used as a quarter-mile drag car. Gawthrop’s friend, Brian Bartel, spotted the car in a Winnipeg Free Press classified ad and purchased the Mach I as a roller without an engine in 1977. After reinstalling an engine and racing it for a year, it sat until Gawthrop purchased it in 1978. Gawthrop installed a new motor and continued to race the car for two years before retiring it from the strip.
In 1984, the Mach I was put into double duty as a street car and weekend racer. This time, it was modified for Stage II Trans Am racing with Koni racing shocks, sway bars and four-wheel disc brakes for running at Gimli’s slalom and road race course.
After a brief period of racing and a move to a new home that included negotiating three kilometres of gravel road, it was seldom driven and eventually placed in storage. In 2005, following urging from family members, Gawthrop decided to put the car back on the road. “What started out as replacing a dime-sized spot of rust, ended up as a full restoration,” said Gawthrop. This time, the body was prepared and repainted in the original Grabber Blue colour by Frank Safanovs in Woodlands, followed by a thorough colour sanding and polishing to bring out a diamond bright shine. National Parts Depot supplied new black vinyl interior upholstery, headliner, door panels and black replacement carpet, while an Autometer tachometer and gauge panel monitor engine functions. The car sports some interesting factory options including original front and rear spoilers and a specially modified shaker hood scoop from a Boss 302 Mustang.
“The original shaker made it a pain to adjust the carburetor, so I had Jim Frazer build an aluminum box under the hood that held the scoop to the hood and left the carburetor free for tuning,” Gawthrop says.
Under that hood is a 351-cubic-inch Cleveland V-8 engine. Custom-built, balanced and blueprinted, its 300-horsepower factory rating is eclipsed by the current 525-horsepower output recorded on an engine dyno. Featuring a stout racing camshaft and ported and polished cylinder heads, it breathes through an Edelbrock Torker aluminum intake manifold and Bolaws 750 carburetor. Because the car is so low to the ground a set of custom headers were constructed and installed by SanDale Fabrication and lead to a three-inch diameter aluminized custom dual-exhaust system with Turbo mufflers. A high-performance MSD 7AL ignition system fires the spark plugs to the engine’s 8,000 r.p.m. red line, while a Weiand polished aluminum water pump and aluminum radiator handle the cooling chores.
Transferring all that horsepower and torque is a McLeod clutch, aluminum flywheel and Ford wide-ratio top-loader four-speed transmission with Hurst Competition Plus shifter leading to the Fab nine-inch housing, Strange aluminum centre section with 3.60:1 ratio, 31-spline Detroit locker rear axle. To keep the Mustang sure-footed, the suspension was upgraded to Total Control’s tubular upper and lower control arms up front with rack-and-pinion steering and three-link rear suspension with coil-over adjustable shocks at all four corners. The brakes were upgraded with Baer calipers and slotted rotors. Rolling stock consists of 18-inch Billet Specialties wheels, wrapped with Goodyear Eagle performance radial tires.
Since it’s completion the Mach I has seen a few shows and cruises. With just 31,000 original miles on the odometer, this Mustang wears all its factory sheet metal and has not seen rain in the past 20 years. A true Pro-Touring build, it’s fast, but thanks to the suspension and brake upgrades it also handles and stops just as well.