Within three years of it’s introduction sales of Ford’s “secretarial” pony car the Mustang had peaked at over 600,000 units per year and there after they fell sharply to level out at the 120,000 annual sales level.

For 1971 the Mustang grew in every dimension except height and gained 800 lbs, under the watchful eye Ford Design Product Manager Semon “Bunkie” Knudsen during his 19 month tenure in between jobs at General Motors and White Motor (Truck) Company. Knudsen is credited with pursuing luxury over the youth and performance culture at which the original Mustang had been targeted.

The ’71 Mustangs like the example seen here were 3 inches wider in both body and front and rear wheel tracks which when combined with the inherited height of the original made for a cramped cockpit.

However while the responsibility for the largest and heaviest Mustang of all time was the responsibility of Semon “Bunkie” Knudsen he was merely following the escalation derby that ended up with “option overkill” which saw $2500 vehicles loaded with options that doubled the value and profits of all of the contemporary vehicle manufacturers.

The Mustang Mach 1 performance option included the hockey stick stripes and Magnum 500 wheels, an all time favorite original equipment option.

Part of the justification for the increase in size and weight of the ’71 Mustang was the 7 litre 375 hp Big block Super Cobra Jet 429 cui motor option which could easily be fitted into the engine bay without the costly modifications that had come about from stuffing mid size cars with full size motors, an activity that can be traced back at least as far as the 1964 Pontiac GTO and was dropped on Mustangs from 1972 on. The 5 litre / 302 cui Windsor V8 on this car would produce between 190 and 210 hp depending on the carburetor option chosen.

The Mach 1 name first appeared on a concept Levacar, which offered a Jetsons vision of the future, in 1960. The Mach 1 name first appeared on Mustangs built for the 1969 model year.

Several sources I have read while preparing today’s blog have emphasised that the Mach 1 package was only offered on sportsroof models.

There was a Sports Coupé version of the hard top offered in the Spring of 1971 which included the hockey stick stripes and a black roof without the Mach 1 lettering of which only 500 are thought to have been manufactured.

It is thought that 1971 Mustang sales figures broke down to 83,000 hard tops, 60,000 fastbacks and just 6000 convertibles.

Thanks for joining me on this Ford Mustang Hard Top edition of “Gettin’ a li’l psycho on tyres”, I hope you will join me again tomorrow for a celebrity edition of Ferrari Friday. Don’t forget to come back now !