You may want to have someone with more experience take a listen to it. There is a whole lot of difference in dealing with a problem with the cam or valves, than one in the bottom end. It is easy enough to pull the head, haul it to a machine shop and re-install, or just replace if bad enough. The bottom ends are pretty stout on these motors. If it has not been abused, trashed with coolant,sludged etc there could be another 100k or so miles left in it easy. If the bottom end is trashed, then the problems and clearances involved with fitting new bearings, pistons etc are best left to an experienced machine shop. Very expensive. Better to drop in a junk yard motor, as others have suggested. If you can not find a cheap one locally, check around there are a lot of nice ones out there. A lot of yards will ship, and the freight charge if picked up at a local trucking company terminal is usually not too expensive.
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Gary Gilliam Sumerduck VA, '94 940 na Regina 160k '86 240 190k