I just bought a high compression (13.5:1) piston because a mechanic friend recommended it and the FMF Powerbomb header. Haven't gotten the pipe yet so was curios as to what you guys think - Is the Powerbomb the best pipe for the 05 YZ250F? Should the muffler be replaced when upgrading the header pipe? From what I've read, the jetting only needs to be tweaked, but I have heard so many different opinions on the higher octane fuel that I don't know what to do there either. Curious to get others opinion here.