In my opinion, that car could only turn in a time like that off a cliff
That car had to be well into the mid 4000lb range. It was a boat.
After reading further. The folks at pontiac recurved the distributor, rejetted the carb and had a special head gasket which apparently raised the compression. Even if they somehow got anothe point in compression and faking the engine to think it was advancing even more with the curve, I can't believe that thing was putting out 500 ponies through stock exhaust.
Oh Well