I guess you have to assume that the current exhaust is a bit of a restriction, and you won't be restricted on the intake side.
With the HP levels you are running, I've always heard that 3" is the ticket, and big primary tubes on the headers is the norm.
Guess I was treating the exhaust side like the intake side - course maybe I'm nucking futs...
What do I know, I'm still in the 14's...