I have this document dated 9/72 which details absolutely every specification on the Lemans and Grand Am. I got it from GM Canada but it is a US document because the Chevrolet engines are not listed. Other than that is has everything you ever wanted to know about these models. It is so detailed it even tells you what speed the car equipped with the various engines and axle ratios should kick out of passing gear. For example, 400 CID V8, max kick down is 74 mph and max upshift is 80 mph.
Another thing is that it also deals with 455 SD specs and this engine was never released to the public. The engine chart is very detailed and shows HP with and without dual exhausts, compression ratios, and transmission and axle ratio combinations.
