Often, big changes are accompanied by mixed emotions. Typically, consumers attain a certain level of familiarity with a product as it is and want it to remain that way. As such, in the automotive industry, it's a gamble to plot a daring new course when designing the next generation of a particular line. Nevertheless, redesigns are imperative to keep the model relevant in its market.
In response to sagging sales of the mid-'60s fullsize Grand Prix, Pontiac's General Manager John Z. DeLorean decided that not only should the line be redesigned, it should also be downsized. While the word "downsize" normally has a bad connotation, in this instance it was just what the doctor ordered. For 1969, DeLorean's uncanny sense for what the market wanted proved accurate. The Second-Generation Grand Prix was developed using an extended A-body chassis, designated the "G-body," and featured a 118-inch wheelbase. From this new chassis, a thoroughly modern GP rose with a fresh, athletic long-hood/short-deck look mixed with classic Deusenburgesque styling.

The Grand Prix's new-for-1973...

The Grand Prix's new-for-1973 redesign blends elegance and function. A more practical hood length was used with the redesigned front end, and distinctive panel creases were added to the sides, eliminating the somewhat slab-side look.

Redesigned for 1973, the dash...

Redesigned for 1973, the dash layout is a work of art. The air of performance is provided by the optional $39 "Rally Gauges with Clock" filling the pods placed directly in front of the driver, and the African crossfire mahogany insert adds the luxury look.
Under the hood was the base 350-horse 400 for the Model J or the upscale SJ's standard 370-horse 428. Manual and automatic transmissions were available, and a 390-horse 428 H.O. with an automatic or close-ratio four-speed manual was optional.
The market responded to the new style and performance of the GP with a sales increase of 354 percent-112,486 for 1969-reestablishing it as the leader in the luxury/performance market.
For 1970, the GP was mostly carryover, save the 370-horse 455 replacing the 428 and other small details. Sales dropped to 65,750 units, most likely due to interdivisional competition coming from Chevrolet's new Monte Carlo and Oldsmobile's Cutlass Supreme. In 1971, there was an updated look with single headlights on each side up front and abbreviated boat-tail styling out back, but sales continued to falter with just 58,325 sold.
The next generation of Pontiac's personal luxury/performance coupe was slated for '72 production, and with it came the hope of reinvigorating the line. Then, in the fall of 1970, a labor strike put a halt to all production on '71 models. This delayed the Third-Generation's debut to 1973. Despite only minimal changes in the look of the '72 model, production increased to 91,961. Don Keefe, in his book Grand Prix Pontiac's Luxury Performance Car, credits economic recovery as the impetus for the sales surge.
Riding the crest of the sales wave was the fresh '73 model. This all-new GP ushered in the era of platform sharing for the A- and G-bodies. Now based off the new A-body, 116-inch, wheelbase four-door chassis, it featured a colonnade roof with fixed rear opera windows, in response to new government rollover regulations. The result was a stylish, formal roof appearance.
At first glance, the GP's new design is similar to the previous generation with a dramatic hood shape and somewhat abbreviated boat-tail styling in the rear. With a longer gaze comes the realization that all the exterior proportions are changed. The most notable ones, aside from the roofline, include the shorter 116-inch wheelbase; a shorter hood; and new grilles, bumpers, and taillights. The overall appearance is wider (3 inches) and more aggressive with body-side character lines that accentuate the wheelwells.
As was true in 1972, the standard engine was the 230-horse 400 with the 250-horse 455 in the SJ. The Super-Duty V-8, intended as an option for the Grand Prix as well as the GTO and Grand Am, never came to fruition and was offered only in the '73 and '74 Formula and Trans Am. The '73 model year was the first to use the small 1.66 exhaust valve on the D-port 400 and 455, the Exhaust Gas Recirculation (EGR) emissions control system, and 5-mph front bumpers.
The response from the public was overwhelming. Sales increased by nearly 62,000 units over the previous year to 153,899, breaking the previous sales record set in 1969.

The new colonnade roof style...

The new colonnade roof style was Pontiac's tricky way of blending in a larger B-pillar while maintaining the look of a coupe. Don Miller's '73 has the optional black Cordova top.

Another option Don's Grand...

Another option Don's Grand Prix was ordered with was an A/C system. In 1973, this would set buyers back a cool $431.

The all-original Pontiac 400...

The all-original Pontiac 400 has never been modified or rebuilt. It's hard to believe that this GP has accrued only 21,700 miles in 35 years. Its only obvious change is the addition of a modern battery.