3800 1997 supercharged pontiac grand prix gtp

looking to get more performance out of the car. Thinking a performance chip
but skeptical of horse power of chip when the car is stock 240-280 stock. I
heard about changing the pulley on the supercharger, going to a down pipe 3
inch or adding cold air intake. Headers were also mentioned to me but all that
i said probably would blow the motor up.