Probably for a heavy street car with 3.42 Gears and a very streetable converter. Definitely not a priority drag car.

with a 4.310 bore and 510 cubes I'm guessing its some kind of offset ground (2.200 BBC journal) factory Cast 455 crank.....So keeping the revs down and the torque up makes perfect sense to me.

So Because of that, I'm thinking the "small" intake lobe is the built-in Rev limiter for the combination. Thats a LOT of lift for that short of a

Pontiacs tend to like wider Lobe Separation angles and the cam in fairly late compared to a BB Mopar, I never understood exactly why,