It is likely an Izusu. You can go to an Izusu dealer, Hitachi dealer,or maybe Deere dealer. If the gasket blew there should be over heating as well as air bubbles in the rad. If it really blew it would blow coolant out the rad with the cap off. If you have oil in the rad or coolant in the oil pan, there is a chance that the engine oil cooler is leaking. If there is coolant at the head to block the gasket is leaking, not blown.