How fast do you want to go? Is the car a stick or auto? The easiest, and least expensive way is to upgrade the intake, exhaust, and ignition systems. You could do numerous things to the tranny, if its an auto. Change the rearend ratio.....etc. As far as the engine, I would investigate the cost involved for a bigger cam. Most companies will sell regrinds, but not a new cam. I have upgraded my "sprint" with a K&N air filter, Pertronix ignition, and dual exhaust. See also the NOS system on this website. Many ideas, e-mail me to discuss more.