Depends on how much money you want to spend. Aside from opening the engine up and doing a complete re-bore, with new heads, no one thing will increase power very much. Each thing you do adds to the equation. Dual exhaust will help, but not much. Free flow air filter will help but only at high rpms. This engine has too little power for this size car. The 350 would be a better choice. Go to www.summitracing.com for some ideas.