How about running a spec crappy tire and limit the width? Your grip and power will be limited to what those tires can take. No sense running a $5K suspension and a $10K engine...[/b]
A local circle track group has a class called "Strictly Stock", and they mean it. Street tires and no mods except for mandated removal of all glass. Guys will drive a beater to the track, take a hammer to the windows, don a helmet and they are good to go.