I have a chance to buy a PSI brand pipe for one of my Exciter project sleds real cheap and was wondering if anyone has any experience with them? This is an 89' model. The carbs have 300's main jets in them. I also have an Aaen pipe that I can run and was told to increase about two sizes which would be 320 but the book calls for 320 stock in the carbs to start. Any thoughts on what I need to do?