In Part I, we began outlining the differences between the '70-73 Firebirds in terms of sheetmetal and body/component construction. Part II will finish the "cosmetic" evaluation.
When it comes to restoration time, an assembly manual is likely the best source of information as to how the Birds (or any other Pontiac model) were put together. These manuals contain everything from the basic drawings of the component assemblies to torque specs, part numbers, production changes, and even lubricant types to be used and where. Unfortunately, they're getting hard to come by, and reprints are no longer available through most aftermarket suppliers. A good guide that's still offered for the unit body of the Firebird is the Fisher Body manual. However, these are more generalized in terms of information provided (though they do offer useful installation and adjustment information on door, trunk, window, and other component assemblies) and only cover the Bird from the cowl rearward, which is what Fisher Body shipped to Pontiac. Sub-frames, fenders, hoods, etc. were installed on the assembly lines at GM's Norwood and Van Nuys plants. Speaking of those two plants, there may be minor (likely very minor) differences between Birds of the same year built at these plants. For instance, the '72 assembly manual shows that one of the bumper L-bracket bolts on Van Nuys cars is to be installed from the opposite direction as those on the Norwood cars. If anyone is aware of any major differences not shown in these articles, again, please let us know and we'll include the information in the upcoming articles.
One item of interest found...
One item of interest found on this '73 assembly manual sheet is the cancellation of the rubber fender skirt seals. The sheet's date is 10-8-71 however, there is no clear reference to the date of the cancellation note, nor is a part number for the seals indicated on this sheet. I have seen these on at least two '70 Trans Ams purported to be correctly restored to original specifications and have a "feeling" that they may have been used up through the '71 or '72 model year cars.
When it comes to fenders,...
When it comes to fenders, early Bird owners have to be careful when buying used. Even though the contours of the fender skins are identical, there are differences. For '70-72, the area just inside of the hood is different in that there are no holes stamped out for the '73-up fender brace.
The '71 fenders are unique...
The '71 fenders are unique because of the fender vent shown here. Note that '79-81 fenders also have extra holes for the urethane wheel opening spoilers. Later fenders also used a slide-on clip for the hood hinge bolts.
All '70-73 fenders be it Firebird,...
All '70-73 fenders be it Firebird, Trans Am, Formula, or Esprit will have this pair of valance panel brackets spot welded to the lower leading edge. Fenders from '74 and later will not have these tabs. For those converting later fenders for '70-73 use, these aren't that hard to fabricate.
You can also remove them from...
You can also remove them from your rusty originals before you scrap them and weld them to the later style-guess what the author did! Depending upon year and type of header panel, the later fenders may also have one of two or three different types of channel brackets with holes welded to the upper leading edge; some trimming of said channels may be necessary.
Though outwardly similar,...
Though outwardly similar, the fenders for all '73 Firebird models are unique. Of course, when restoring an SD Formula, be prepared for a lot of questions as to why you want a plain fender and a Trans Am hood.
Here's why the '73s are set...
Here's why the '73s are set apart from the rest. Not only will they have the pair of valance panel brackets shown previously, they also have this pair of raised holes for the fender brace. Later fenders don't have the valance brackets, and '70-72s don't have this fender brace mounting pad/holes. Good '73 fenders are as much fun to find as the vented '71 Formula fenders.
Here is an original '70 nose...
Here is an original '70 nose bird emblem, sadly, it hasn't weathered the years well and the red border on the wings is long gone. It is not available in reproduction form. These were used for the '70-71 model years. Based on the research conducted for this article, it appears as if the nose bird emblem was dropped for '72-73, then re-issued for '74-76. In 1977, the Pontiac arrowhead replaced it. None of the Pontiac promotional and advertising material that the author has examined for the '72-73 model years shows the nose bird.
Here's a reproduction version...
Here's a reproduction version of the basic Firebird fender emblem used for '70. (Courtesy of Ames Performance Engineering)