hmm, it's not gonna make too much of a difference, unless you do all the headwork, because getting a bigger throttle body will just create a airflow logjam somewhere else. If you're gonna P&P, get cams, new intake manifold, or even something like up your comp ratio, then getting a TB would help but on it's own it's prob not the most efficient mod.

what else have you done to your car? bolt-ons? suspension? brakes? wheels/tires? what will you eventually do to your car? some questions to ask before you go ahead with this.