One mans flow bench is nothing like the next guys. I like the Dart Wilson Out of box its a nice intake. I've did the hurricane, super victor and dart wilson all on a 23 degree under headed 434 Dart was well faster. Them heads were worked over by Rons a bunch and still IMO were not enough.
I'd be amazed if you seen 3 tenths with the head change without milling them down some to sneak some comp out of the motor. Just remember we race on a track not flow benches or dyno's, do both help yes they help a lot but they also give you the chasing #'s factor its easy to inflate #.