The 1968 to 1972 GM "A body" cars are arguably the most popular and recognizable of all GM muscle cars. Two reasons are the sheer numbers produced and variations that were available.
Who didn't either own or know someone who owned a Chevelle, Cutlass, Lemans or Skylark? This was both the high point and low point of the muscle car era. Although there are other model years that are my personal favorites, I have owned, raced, modified and restored more General Motors automobiles from this era than any other.
These four GM divisions (Pontiac, Oldsmobile, Buick and Chevrolet) were in more direct competition with each other through the 68-72 years than any other era, and their engineers had almost as much freedom as the early 60's.
Having owned each of these midsize models I can attest that there are
less factory correct components that are truly interchangeable than you
would think. I was always amazed at how many more bolts and brackets the B.O.P. cars had than Chevys. Of course, very few people could have owned or can be an expert on all the models available in this "golden age" of General Motors automobiles. Therefore, I will use factory manuals, drawings and catalogs for references. In the categories below I will show pictures, descriptions, and applications (broken into car lines) based on this information and New Old Stock or OEM components whenever possible.