Manifolds: Up until now all upgrades I have listed can be done by most anyone. This however is a VERY extensive upgrade and should only be done if you're an absolute power freak or if you have allot of time on your hands. This upgrade involves removing your stock exhaust manifolds from the engine and having them ceramic coated inside and out. The benefit is that it reduces underhood temperatures by 100-120 degree's. An underhood temp drop means a colder intake charge, which means more horsepower. Reduced engine temp means longer engine life and improved exhaust flow is also attained because of the coating on the inside of the manifold. It cost's $145.00 and you have to send them to Performance Coatings Inc. to have it done. Information about there service's can be found at http://www.performancecoatings.com. After all that work you get 5-8HP more.