Imo, there must be some fairly substantial limitation in the induction/exhaust system(and possibly combined with lowish CR) for none of those cams to get the motor to make 1hp/ci.
My guess the head but it's a Dart stock replacement head that flows slightly above stock, that's why I think people don't believe dodge power numbers cause they compared they to old 350 pre major aftermarket head support of the 350, I doubt many old school 350 made over 400 hp.