Rear end Gear HELP

I have a 98 gt with an aode, so that's with a 3.27 rear end. I hear that changing the rear end gears make a huge difference in performance. So I was thinking of getting a set of 3.73 put in. Right now it's stock, but later on if I got say close to 500 hp would the 3.73 still be the right thing to have. I'm looking for all out acceleration but aleast 130 to 150 topend.