3.30's thats weird, i would have sworn your stock should be 3.55's (that's what I got).
I put numerous upgrades on my stang, and with that knowledge I would suggest 3.70's or 3.90's. If you put 4.10's on you will be taking them down when you up a SC on.
2007 GT/CS Convertible, Modifications: Dyno tuned. JLT CAI. 4.10 Gears. Edelbrock SC. Eibach Pro Kit Lowering Springs. Cervini’s Concept Hood c/w Custom Paint. Magnaflow Tur-X X Pipe and Magnaflow Axle Back's. Ruff Racing 20" Wheels, Nitto Invo 255 F, 295 R.