My 99 WR400 frame is starting to rust through on the underside of the footpeg supports. It's from a combination of taking a beating from coming down hard on rocks and the resulting rusting of the bare metal. Anyone know what year YZ/WR frames can be used instead? I checked the Yamaha site and the frame numbers from 98-02 for the WR and YZs are all different by one number (or letter). Any help would be appreciated. Thanks.