Mike,
I just got off the phone with Ram. With the power you are running you will have to step up to a much higher grade clutch. They are talking changing the complete setup to more of a street strip setup. They did not recommend changing just the disc because the pressure plate has seated to the disc in there now. The life of the new disc will be very short because all of the pressure plate will not be contacting it. If you need to call me you can reach me toll free at 877-276-8081.
David Kee
http://www.4speedtoploaders.com