Don't rule out shade tree. Haven't gotten a recent dirt catalog, but I got a pro-light piston kit for my xlt from them. They where almost 50 buck's cheaper then everyone else was, and my shipment arrived ahead of time.
1-888-742-3387, free call [img]images/graemlins/laugh.gif[/img] You will have to ask them, don't have any dirt bike aplications in the one I have here, but it wouldn't hurt to ask. www.deniskirk.com has them, there 85 buck's. I'd check shade tree and see if they have them. Both are more then likely going to be cheaper then marshall's.