My old buddy Bills Demon went 9.30's at 3400lbs all steel all glass with a pretty simple 511" deal with -1 heads. Not even very heavily ported -1's with a jacked up 4 link. We shifted it at 6400! One of the many issues it had when we met he was shifting at 7100 because that what someone told him it needed BUT there is more to getting your car to run well than just the engine. But it dont take a ton of power to run 9's at A body street strip weights for sure. I also built a 511" for a 69 RR nothing fancy Indy CNC head and it can run 9.40's all day long shifting at 6800 and that thing tips the scales at 3720. We are talking 650ish HP to make a middle/high 9 second pass in a typical 3000-3100 A body