Stock 1998 GT Convertible Upgrades

[98GTBlkConv]

Hello! I am a new user of this forum, and am, in fact,new to message boards all together. Anyway, if I come off as a newbie, I appologize in advance.

Last fall I purchased a 1998 GT Convertible (only 22k miles). I would like to keep the car relatively stock, but would like to gain some performance from it. I do not intend to take it to the strip, but would like some more hp. I have added a Flowmaster American Thunder Series exhaust, and a K&N intake system to it. I have heard many conflicting opinions on underdrive pulleys, but most seem to think they do not truly increase hp. Additionally, I have considered a chip, but since the car is 5-speed, have heard there is not much of a power gain. Any suggestions that aren't too "radical" would be greatly appreciated.

By the way, I am in need of some new, good tires and would appreciate suggesions. I consider good tires important and would rather pay more for good rubber than skimp.

Thanks!