Pontiac sales hit an all-time high in 1973 with 919,872 cars sold. Wheelbases were standardized this year with 112 inches for all two-door intermediate models and energy absorbing bumpers were required, either by a hydraulic bumper arms or Endura rubber deformable noses. GM called the new models “Colonnade” designs and there were no convertibles.

The 1973 Pontiac GTO was now a tiny subset of the Le Mans series and the new kid on the block was the Grand Am, which used a similar body with a sloping rubber nose and was described as a luxury hardtop. It had lots of creature comforts, but less powerful engines mandated by emissions requirements.

A total of 4,816 GTOs were built, divided into 494 Coupes and 4,312 Sport Coupes. The base Coupe had a rear quarter window and the Sports Coupe had vertical louvres covering that window. As a Le Mans Performance Package, the GTO added $368 to the base $3,406 for the Le Mans and $3,493 for the Le Mans Sport. Engine choices were a 230 bhp 400 cid V-8 and a 250 bhp 455 cid V-8.

A Hurst 3-speed manual or a 4-speed manual (an extra $190) were optional with the 400 cid V-8, while the 3-speed automatic cost $236 more. The 455 cid V-8 cost an extra $57, but could only be had with an automatic transmission. A handling package was available for $4 and a Safe-T-Track limited slip axle was good value at $45. Power front disc brakes were optional for $67.

GTO identification included a blacked out grille with GTO emblem and 400 or 455 on the front fenders. Bucket seats were standard, and a bench seat was optional. All GTOs came with firmer springs, a rear sway bar and moon hubcaps.

With performance options clearly off the table, all that was left were luxury add-ons. A total of 37 were available including air conditioning for $397, an electric sunroof for $363, a manual sunroof for $275, an AM/FM stereo tape player for $363, honeycomb wheels for $123, power bucket seat for $103, rally gauges with clock and tachometer for $100, power windows for $75, power door locks with seat back locks for $67, cruise control for $62, and a console for $59.

Exterior paint colors dropped to 13: Cameo White (C), Porcelain Blue (D), Admiralty Blue (E), Regatta Blue (F), Desert Sand (H), Golden Olive (J), Verdant Green (K), Slate Green (L), Brewster Green (M), Florentine Red (S), Anaconda Gold (S), Ascot Silver (V), Valencia Gold (Y), and Burma Brown (Z).

Eight interior colors were offered and both bench and bucket seats were available. Green ad Beige were only available with the Hardtop bench seat, while Blue, White, Saddle, Black, Burgundy and Chamois were available for other bench or bucket seat interiors. There were no convertibles anymore and three vinyl top colors were offered: White, Black, and Beige.