Save your old filters and take them to NAPA. On the oil filter, most of the Japanese equipment uses the same thread (20 mm, if I remember right). The critical dimensions are the gasket outer diameter, so the filter seals properly on the block, and the overall outside diameter, so the filter fits into the cubbyhole it's supposed to go into. The most critical of the two is gasket diameter; you should be able to go a little larger in overall outside case diameter. (Diesels have more space between the outer edge of the gasket and the outside of the filter than do gasoline engines, by the way.) Usually filter height, how far the filter sticks up off the block, doesn't matter much in a tractor application, unlike many motor vehicle applications. The NAPA rep should be able to find something that will work. Same with the air filter, most likely. NAPA stores have a book that gives dimensions on all NAPA filters. Good luck.