I've been searching around the YZ450 forum for about an hour and haven't found my answer. I just read in the new Dirt Bike about a pro off road racer (forgot his name) who made his CRF450R more rideable by installing a CRF450X head and cams. I would like the milder WR cams for the type of off road riding that I do. I suspect that the YZ cams are what I dislike about this bike in really steep, slow, heavy clutch sections. I've already added the heaviest GYTR flywheel weight and changed my gearing to 13-52 which made noticeable improvements in the slow sections mentioned above. From what I read on TT the '07 WR cams will not fit the '07 YZ so changing the head seems like the solution. I just looked at the fiche and noticed that the base gasket, head gasket, cam chain, and cylinder are the same part numbers for the '07 YZ and '07 WR. Yamaha sells the WR cylinder head assembly that appears would bolt right on. Besides the WR cams what else would I need to do this? Thanks for any feedback/advice.