more horses
 

Just bought my first mustang. Its a 91 gt and was wondering what I can do to make it a little faster. I got about 500 dollars to spare, and want to know what to buy. I do not want nos, so maybe someone can help. Thanks

Gears!!!!

Get some 3.73's. You'll love them. They will make your car feel way faster, plus it is more fun to drive. You can easily get gears and get them installed for around $400. Then put the $100's left over into a underdrive pulley set. Oh and don't forget the K&N air filter.

ditto.
gears and underdrives

then the next $500 will have to go for an offroad h-pipe and catback

Yep, the off road pipe will make a big difference, as long as you have no emissions, if you do then you are stuck to an on road pipe.