Boosting performance on 92' 305.

Anyone know of any free/cheap mods or tips to wring a little extra power out of the 305? I like to tinker, but I don't see investing hundreds of dollars for an engine swap/exhaust upgrade/headers/supercharger, etc when I'll probably only keep the car for another 6 months when I pick up my new SRT-4. I have put in a K&N air filter, and trimmed several inches of radiator shroud to route cold air into the intake. Anything else I should consider? I'm not looking to take on any projects that would cost more than $200 - $300 at a time.