Humongous loss of power after 3,000 rpms, help?

[pro_am]

Hey knowledgable folks of the firebird forum. I'm assuming most of you are familiar with the situation with my pro am firebird. Well i got it running good for what it is, and now it takes off great, has tons of torque it feels like, and good "pull" however it seems to have no horsepower what so ever, especially after like 3g rpm. What mods should i do to the engine to remedy this? Maybe switch out the TBI for carb/intake or maybe a throttle bod spacer with a vortec spin on it? i don't know, any help, thanks!
Jake