440 Camshaft recommendations for up to 6-6,500 rpm?

It seems to me that people forget that a 440 is a big block with a small block cylinder head on it. 440 magnum was rated at 375 hp at 4400 rpm. The six packs were rated 390 at only 4700! Without SERIOUS cylinder head improvement, it wont matter what cam you put in it, it wont make power at 6500, maybe not even at 6000.