Your going to be dollars and mucho time saved to rebuild the C223. The parts are available. You can look at complete rebuild kits by searching Australian Parts Suppliers look under (HOLDEN JACKAROO). The shipping is not that outrageous. Also if you can find a patient parts guy at a Thermo-King Dealership (transport refrigeration) he can order the C223 parts for you. The pan and some other Misc. stuff is different but the engine is going to be the same. The last pup engine that we did, I found quite a bit of stuff at NAPA
ROD BEARINGS-$39.64 CB1093P
MAIN BEARINGS-$70.29 MS1738P
THRUST WASHERS- $9.29 TW470S
CAM BEARINGS -$14.49 SH907S
OVER SIZEDRINGS ? I can't find my part # but I bought them for a 82 ISUZU

Don't give up! They are not complex engines to rebuild.