Ok so I am new to the ls1 stuff I want to do some more bolt on's to my car but have some questions. First off i'd love to do headers, and off road y-pipe but have heard many so you need to tune afterwards is this a must and will the car run fine, second off is the slp cold air kit worth the money or just stick with the slp lid and high flow air filter? Also what is the best cat-back bang for the buck b/c i really like the slp loud mouth 2