I've done some searching and think it will work but want some sort of confirmation. My 98 WR400 broke a valve and messed up everything on the top end. What I need to know is will a 2000 YZ426 cylinder head bolt onto a WR400 cylinder? The cylinder is the only part that is not messed up. I would go with the WR400 head but I have an opportunity to get a YZ426 head at a good price.