What can $3,000 buy for my new GT?

[blue00gt]

How much power you will get from a blower depends on whether you go with a roots style or centrifugal blower. Added to a bone stock motor, most roots blowers get you up to about 360 hp at the crank, while a good centrifugal will get you to around 400 hp but with less low end power. You don't need to get anything else to make them work if you get a complete kit, but every bolt-on that helps air flow will obviously help even more with forced induction.
Even without a power adder you would still have to void your warranty to get up to 320 hp. The following parts should get you close to 60 extra hp power naturally aspirated:
Crane re-grind cams
Full-length headers
Short H-pipe
Catback
Underdrive pulleys
Timing Adjuster
K&N
Throttle-body
Mass air meter