1973 Firebirds

While the muscle car era was ending for all other manufacturers Pontiac would rein supreme for 1973 with the introduction of the Super Duty 455, arguably one of the best engines ever to come in a domestic car.  This engine was directly derived from Pontiac’s racing programs and featured forged pistons, round exhaust ports, a cam shaft with durations identical to the Ram Air IV of the ’69 and ’70 Trans Am, and a provision for dry sump lubrication.  This engine was the fastest American production engine of 1973.  Oddly, although this Super Duty engine was only available in the Firebird Formula and Trans Am it was the ’73 GTO that won Car of the Year in Hi-Performance Cars magazine and remains one of automotive journalisms biggest blunders.  Pontiac built just one test car for the press but never released the Super Duty 455 for the GTO. 
1973 Firebird Esprit
The big changes for 1973 were mostly relegated to the Trans Am.  The blue or white stripes were dropped and for the first time the large Screaming Chicken decal became joined the option list.  This decal would prove hugely popular and would become synonymous with the Trans Am.  Colors were expanded to three with Cameo White, Buccaneer Red, and Brewster Green.  The round port 455 HO of ’71, ’72 was dropped and the standard Trans Am engine became the L-75 D port 455 with the Super Duty 455 optional at a whopping $521.   The base Firebird was still the only model where you could get a 6 cylinder, the Chevrolet built 250 cid inline 6 with the 350 2bbl as the only option.  Esprit, as usual came with the 350 cid 2bbl standard with a 400 2bbl optional.  Except for the availability of the Super Duty 455 the Formula’s offering were unchanged with the 350 2bbl from the Esprit as standard (upgraded with dual exhausts).  Formula 400 added a 4bbl 400cid engine rated at 230hp.  The L-75 D port 455 was the standard engine for Formula 455 with the Super Duty 455 optional.  When you ordered you Super Duty with a Formula the dual snorkel hood was replaced with a bird-less Trans Am shaker hood and scoop.  The shaker hood scoop was no longer functional beginning this year.
The easiest way to identify a 1973 Firebird is by looking at the front grille.  New Federal impact regulations required strengthening the front bumper so the grille was moved forward in the nostrils to accommodate the new bumper hardware.  The grille design was changed to a coarse rectangular grid sometimes referred to as an egg crate replacing the honeycomb pattern of 1972.  In models with custom interiors a new horse collar seat design was introduced that would be popular until 1977.  Lower door panels were now molded in plastic instead of carpeted.  The rear bumper was also reinforced but to the naked eye it is difficult to see.

1973 Production Numbers

  Firebird (Base) 14,096
  Esprit 17,249
  Formula 10,166
  Trans Am 4,802
  Total 46,313

1973 Base Firebird Production

  Engine Manual Automatic Total
  6 Cylinder - - 1,370
  8 Cylinder - - 12,726
  Total - - 14,096

1973 Esprit Production

    Manual Automatic Total  
  L-30 350 cid 2bbl - - 15,550  
  L65 400 cid 2bbl - - 1,749  
  Total - - 17,299  

1973 Formula Production

  Model Manual Automatic Total
  Formula 350 - - 4,771
  Formula 400 - - 4,622
  Formula 455 (L75) - - 730
  Formula 455 SD-455 33* 10* 43
  Total - - 10,166
*High Performance Pontiac, August 2002

1973 Trans Am Production

  Engine Option
  L75 455 1,420 3,130 4,550
  L82 SD-455 72 180 252
  Total 1,492 3,310 4,802
Source: Firebird! America's Premiere Performance Car, Gary Witzenburg page 235

Firebird Optional Equipment

  Option Total
  V-8 Engine 44,943 97.0*
  6 Cylinder Engine 1,370 3.0*
  Transmission-Automatic 39,931 86.2*
  Transmission-4Speed 4,237 9.1*
  Transmission-3 Speed 2,145*** 4.7*
  Power Brakes 40,848** 88.2*
  Front Wheel Disc Brakes 46,313** 100.0*
  Limited Slip Differential 9,309** 20.1*
  Power Steering 46,111 99.6*
  Power Windows 5,357 11.6*
  Air Conditioning 30,597 66.1*
  Adjustable Steering Column 7,020 15.2*
  Vinyl Roof 12,443 -
  Radial Ply Tires 2,871** 6.2*
Source: The Fabulous Firebird by Michael Lamm except as noted below
* Source: Firebird! America's Premiere Performance Car by Gary Witzenburg
**Source: Estimated based on percentages published in Witzenburg's Firebird!
***Derived from subtracting Auto and 4 speed from toatl production
Note: Numbers published in Fabulous Firebird may not correlate with percentages published in Firebird! America's Premiere Performance Car.
1973 Trans Am and Formula

What else was happening in 1973

The Arab oil embargo causes gas shortres and price increases.
The World Trade Center becomes the worlds tallest buildings.
Top movie: The Exorcist
Top song: Tie a Yellow Ribbon by Tony Orlando and Dawn
Egypt and Israel engage in the Yom Kippur War.
Skylab is launched
Marlon Brando turns down best actor Oscar for Godfather
Nixon takes responsibility for Watergate