I have not ridden the CRF but I have done extensive testing of the WR450 vs the YZ450 cam set up. I have a YZ450 Exhaust
Cam and after riding a few hundred miles on it I have put back the WR450 cam back in the bike. I lost bottom end, and gained a lot in the middle to top end. The bike really reved quicker. I was not good (fast) enough to control the wheelspin in the woods ( I even had trouble keeping the front wheel
down since it seemed to want to run best in the midrange) and I hated the loss of lugability on the bottom end. The stock WR450 is plenty scary fast in the woods for me. The jetting changes require a YZ needle and larger main to complete the conversion. I still have the YZ450 cam wrapped in an oil soaked zip lock bag. I would recommend it for A woods riders only or any level of sand/ desert type riding. Any of you desert guys (TT members with 200 plus posts only) out west let me know if you want a deal on this cam by PM'ing me. I will ship it to you and if you like it send me the money or send it back. I trust our regular TT members they are the best!