here ya go http://www.ebay.com/itm/Yamaha-Warrior-350-Engine-Crank-Cases-1998-Warrior350-Raptor-350-Y5-/120977954650?pt=Motors_ATV_Parts_Accessories&hash=item1c2ad9175a&vxp=mtr
ive seen this not sure of quality and not sure about price but?? http://www.maxrpms.net/shop/index.php/atv-utv-kits/atv-yamaha/raptor-warrior-350/warrior-400.html