Anyone have a proven aluminum headed, 500 hp, 440 six pack build?????????????

500 HP 440 is like a 400 HP 360, really takes little effort to get that kind of power from the displacement meaning there are a lot of proven ways to get there and you don't need any trick expensive parts. Just a good combo of cam, heads and headers/exhaust (and having decent compression, not a 7.8:1 smogger although those still can make serious power). IMO at that power level a six-pack setup won't make much difference in HP compared to a modern single-4-bbl.