I have an 03 YZ450 that I am trying to improve as a woods bike. I have added a DRD 8oz flywheel and GYTR Ti muffler & lowered the gearing, but It still has too hard a hit for my taste. In searching past threads it seems the 03has the hardest hit of the 1st gen motors, so I'm looking for other areas to broaden the powerband. The cams use the same part numbers for 03-05 which leads me to believe the difference is ignition mapping. My question is do the CDI boxes interchange and if so, which one would offer the broadest power for the woods? Also I'm considering swapping cams and if I understand correctly going to a WR exhaust cam will broaden the powerband at the expense of a few overall ponies? Thanks guys.