actually you should be the first to change gears. trust me i have wanted to, but don't know where to start.

i think a nice set of 4.10 or 4.11 would give the car a nice feel and quite possibly a respectable 1/4 mile time, and alot faster acceleration. all the sprintbooster does is increase the throttle response, which is well just a feeling you receive and wouldn't increase any quarter mile times or 0-60 times ect...