1970 Firebird And 1973 Firebird - Shop To Swap: '70-73 Firebirds

Editor's note: Shop to Swap will be a multi-part series that discusses the physical differences between the '70-73 Firebirds with an eye towards which parts can be interchanged between the years to make your swap meet rummaging more productive.

There's a general perception in the collector car "world" that, aside from model and option content, little differentiated the '70-73 Firebirds. Hobbyists with intimate knowledge of the early years of the Second-Gen Birds have learned otherwise, however. Without delving too deeply into the arcane numerical sciences reserved for those who can recite from memory the exact dates, times, work-shifts and notepaper on which said changes were issued, we'll outline the differences between the '70-73s. Armed with this information, when restoration time arrives, you won't be stuck with a pile of parts requiring major metallurgical manipulation.

Though this article focuses on '70-73, in some instances we'll point out the parts for '70-73 that are identical from later years. And we will discuss the ones that are usually referred to as fitting '70-81 but really require you to break out the Sawzall, torch, grinder and Bondo if it's for a '70-73!

Up front is where you'll find the largest number of differences, especially when it comes to separating the '70-72 Firebird models from the '73s. Aside from styling changes, the primary reason these differences exist can be attributed to Federal Motor Vehicle Safety Standard (FMVSS) 215, titled "Exterior Protection." Standard 215, effective Sept. 1, 1972, required that passenger vehicles beginning with the '73 model year withstand a 5 mph front and 2.5 mph rear impact as measured against a perpendicular barrier without sustaining damage to safety-related items such as headlights and fuel systems. Over the years, FMVSS 215 has been revised and amended and incorporates aspects of the Motor Vehicle Information and Cost Savings act.

However, for this article's purposes, it was in effect in its most basic form and was the main reason that many unfinished Pontiac F-body cars on the line after the GM strike of '72 ended were scrapped. The amount of work required to retrofit them as '73s wasn't likely cost effective. Standard 215 is also the reason the '73s are the most "unique" of the '70-73 lot.

While we're on the topic of the Feds and regulations, it's interesting to point out that from the inception of the Second-Gen line, heavy side-impact beams were installed in the doors, though these weren't actually required until Jan. 1, 1973. The National Highway Traffic Safety Administration issued FMVSS 214, establishing requirements for side-impact protection based on static test scores. (Crash test dummies in stationary vehicles were treated to a nice shot from a deformable barrier moving at 33.5 mph.) Pontiac was one of several automakers to accept and meet the standard a few years prior to it becoming mandatory.

This article will stick with the body and will continue with it and exterior dcor related items in the next issue. In the following issues, we'll cover engine and chassis/driveline and interiors. Please note that the information contained herein is not given as the final word. In this business, we know better than to say "always" or "never." If you have proof of anything that is contrary to what's in print here, or know of something that has not been covered but should have been, please contact us ASAP so that we can bring it to light in the articles that follow.

'70-73 Part Number Identification ChartTo assist you in your early Second-Gen Firebird endeavors, the following is a brief breakdown of the part number prefixes used from '70-73.