I have to agree with Blair to an extent on this. I have almost given up on trying to "science out" which one is better on a given combination - even just on the dyno, much less a car. One of my best running ones on the car was a Street Dominator that had a 4500 flange cut into it with a bit of weld and some epoxy, along with some spacers - a plastic four hole under the carb on top of an open one (the open one had a few spray bars in it - but that's another story).
On the dyno, with fewer variables, I have seen the better intake on every measureable feature get beat by one that pretty much looks like crap. I've also seen two intakes that looked so radically different that one simply "had" to deliver different results than the other - and you could overlay the graphs and not tell which was which. Put it on a car and you have a bunch more things going on that cloud the decision even further.
Just pick one that "feels right" and flog on it. Odds are you won't be disappointed. It's not a super hard part to change out if you have the money and patience to try things. Just be prepared to be surprised.
