If you are looking for squezzin more out of your Raptor you should keep an eye on the guy's @ Powroll http:// http://www.powroll.com
They have been doing Four Stroke Performance for a very long time and they get it right before they sell it. They are finishing up a new pipe for the Raptor that is supposed to breathe as well as an open pipe, but is spark arrested. Also look for the Nitrous kits coming soon. Currently they have an oil cooler and piston kit to pump up the compression with the stock bore.