Well, taking the top speed limiter off itsnt really a good idea, especially on a GT (I used to have one)
You can put the Supercharger on, its called a Top-Swap, and it's fairly extensive to do, you'll need a good bit of know-how.
I turbo kit is going to run you $3000 +, not to mention needing a HD transmission.
You best bet is to read through this
http://www.grandprixforums.net/safel...car-17482.html
If you want it alot faster, you're best bet is to find a GTP, or if you have the money, Turbo it.
You'd probably be happy with a HV3 Insert, and a good tune-up.
ZZ Performance
