I found my manual on ebay. They're not that rare. One every 2 months on average. Search for C223T engine or trooper diesel. There are occasional bearings and rings available on ebay, but you almost have to have disassembled and mic'ed your engine cylinders and bearing journals in advance because they're sized in " so many thousandths " over the original size. There are Isuzu industrial outlets for construction equipment and OTR refrigeration units that frequently have different knowledge on interchange and suppliers than do auto rebuilders.