I am looking to possibly change from my XR's only header and exhaust. I have a big-bore high compression piston, valve job with ported head, HRC cam, etc. and I like the way the XR's only exhaust performs, however I am looking for something quieter....Any Suggestions? I am hoping to not loose too much power, even putting a closed end cap with 12-16 discs results in a loss at the throttle. I have no experience with any other exhaust...I was looking at Approvich, Big Gun, FMF, White Bros, etc.