1976 Chevy Corvette Crankshaft bearing

I encountered a squealing sound after about 20 minutes of driving. I immediately parked the vehicle and shut off the engine. The oil level checked good, with less than 2000 miles since the last oil change. The vehicle sat for about an hour, when started again the engine ran normally and quiet. I drove the vehicle about 5 miles to a garage and parked it overnight. The next day I pulled the oil pan and looked at the crank bearings, one had a slight bluish color. The magnet in the oil pan had a very minor amout of shavings in it. I replaced the oil pan, put new oil in and drove the vehicle about 3 miles to my home. The engine ran quiet and smooth.

My question is. What is the risk of just replacing the crankshaft bearings and a possibly installing a synthetic motor oil, or something of that nature. What is the risk to the rest of the engine to try this approach. Or, should I try an oil additive and not do anything untill the problem gets worse. I really can't afford to replace the crank at this time. I want to drive the vehicle on short weekend drives, but can park it for the time being if necessary.

Thanks. Bill