Bailey,
Just did the timing change on my '01 WR426. Not a terribley hard job, just take your time.
First off, have you changed the needle & jetting in the carb or are you still stock?? There is a huge power difference in getting a better needle & jets!! You'll want to do the jetting & needle BEFORE you do the timing change. You're not going to hurt anything if you don't, but you won't notice much if it's not getting enough fuel. Plus, the power increase from the needle may be enough to get you to the next level of performance without doing the timing right now. My bike flat hauls the wood...4th gear standing power wheelies are NO problem.
Where are you located and what is your elevation?
Scott