I researched quite a bit when I bought my car a couple months ago.
The general idea I got was...
Tune only - 380-395 range (intake adds a little in there)
Tune/intake/ intake manifold - 400 - 415 range
Tune/intake/ intake manifold/long tubes/ OR pipe - 415 - 430 range
I didn't research longtubes too much as I don't plan to do them for a while, however the above was the general idea I got, I could be wrong, but then again... at least I searched
I'm hoping to get to 400whp with my boss IM/ steeda intake/ and Lund Racing tune. I feel my goal is achievable, I try not to get too hung up on dyno numbers as they vary widely.