For Bunkie Knudsen 1973 was his watershed year. Gone from Ford, he would see his successor, Lee Iacocca, the ultimate small Mustang supporter kill off the big Mustang in in favor or returning the marque to its roots.

For then-Ford President Seman "Bunkie" Knudsen and friends 1972 was nothing to write home about and 1973 was about to become worse. Knudsen, at one time, the General Motors wunderkind, lost his battle to remain president of Ford, the automaker to whom he jumped when he was passed over for the GM presidency in 1968.

Knudsen and Shinoda were responsible for reversing the course of evolution at Ford with their "big platform" Mustangs. They also brought on the horsepower race. Ultimately, the pair was responsible for the oversized, bloated and generally less-than-well-received 1971 to 1973 Mustangs that featured "fastbacks" that were almost "flatbacks", notchbacks and convertibles. At one point, there were at least eight or nine different six and eight-cylinder engine offerings, ranging from a 220 horsepower inline six to the fire-breathing, cement ripping Boss 351 that put 429 horsepower, at one point.

The year 1973 was to see the demise of the "big platform," Knudsen's sendoff from Ford and the return to ascendancy of the ultimate "small platform" proponent Lee Iacocca, generally credited with initiating the Mustang car as a "secretary's car," Gene Bordinat, vice president of design at the time, told auto commentators at the time.

In 1973, the Mustang was a still hefty 3,600-pound vehicle that was facing not only its own bloat, but further bloat caused by then-new federal safety, emissions and pollution control standards. In the face of this, it was amazing the Mustang lasted as long as it did. Sales were up somewhat thanks to the 85 percent sales increase of convertibles. Still, at the end of the year, Mustang sales were only 135,000.

Changes, except for those mandated by the new federal safety, pollution and emission standards, were fairly minimal. The Sprint package, which appeared in 1972, was gone. In its place, the base model and Grande were given looks more like the Mach I. A new "Décor group," featuring twin hood scoops in black or silver, also appeared. The Boss 351 retained a functional air ram, but only on the two-barrel (deuce) version and radial tires were now optional. And, there were some minor trim changes such as the new larger eggcrate grille with integrated parking lights on the base and Grande. The changes made them look more like Mach I's.

Fastbacks sported a silly sort of half vinyl roof that really wasn't functional and only added weight to the Mustang and the mag wheels everyone had expected on Mustangs were replaced by polished aluminum wheels.

Front disc brakes were nearly standard across the line with rear drums that were also enlarged to handle heat and stopping better.

Further, the federally mandated NOx controls were now in place and they choked the power available. Ford's system of PVC and EGR, used in combination, permitted leaner carb settings, but it knock the stuffings out of horsepower and effectively ended the pony car wars.

Ford's Mustang did use some innovation when it initiated the federally mandated bumpers: the automaker color-keyed the new brooding lips to the car.