cway the gasket is for where the cat and your new exaust go together, and the insulator is the rubber part that goes from your exaust to the hanger, it looks like a tear drop shape. arent the mufflers already welded on to the exaust? where did you get the exaust from? good to hear that you did the kkm, but you should have done the exaust first, but it is no big deal. if you did the kkm yourself you can definatly do the exaust mod no problem.
