so does my bicycle

 

and my legs...

 

i just wana squeeze power without decreasing my gas mileage. the po rebuilt the motor, headers, and an exhaust. i made an intake. i was thinking of a cam but worried that would limit my gas mileage. any comments?

 

It does require extensive mods to see a substantial improvement, however you can get by without spending the whole bank if you can do it yourself. I think I've actually spent about $2300 for all my engine modifications. but I have several hundred hours tied up in it. I figure if I paid for all I've done, I'd have spent well in excess of $6000
Generally increasing power means increasing your engines ability to burn fuel. which means more fuel consumption. As long as you don't go overboard, and can keep your foot out of it most of the time, you can increase power output and get similar fuel mileage, but usually if more power is available then it gets used, leading to worse gas mileage.

A slight upgrade in the camshaft, along with a slight increase in compression ratio can give a power increase with out hurting fuel economy too much.