Reply to bruce oz:
hello , i had my rings for the 22 made ,local engine rebuild shop sent size of to the maker ,$9 oil ,$7 compression ,you could ask your local shop ,bruce oz
Chad - Hastings are usually the choice for people seeking older and obsolete piston ring sets .. they show the P/N for the 22 engine, but I do not see oversizes mentioned. Maybe a call will clarify the availability.
http://www.hastingsmfg.com/RingFinderMasterDetails.aspx?AppMACD=CAT%20TRAC&AppMOCD=CATERPILLAR%20Tractors&AddText=(Never%20use%20Plated%20Rings%20in%20Plated%20Cylinders)(Listed%20by%20Cylinder%20Diameter)
I have also had excellent service from an eBay seller trading as Northern Auto Parts Warehouse (seller ID - mpcentral) .. they sell a large amount of overstock cheaply on eBay, but they are also keen to supply anything they can get hold of, that isn't listed on their eBay stock list.
Jeff is their guy answering the emails .. he is helpful, on the ball, and his quoted prices are good. He is in the process of supplying me with a number of Continental F227engine parts for a Cat forklift, and his pricing was near the best of all I got quotes from, particularly on the rings.
http://stores.ebay.com/Northern-Auto-Parts-Warehouse