Is the crankshaft round and smooth on that cylinder? If so, you can just replace the rod from the bottom. Pull the piston down in the cylinder far enough to expose the wrist pin, loosen or remove the clamp bolt, and slide the wrist pin out by shaking the rod from side to side. Measure the crankshaft with a micrometer to see if it's been ground undersize, and buy a reconditioned rod with the babbit sized correctly for the crankshaft diameter. If more than one rod bearing has problems, I'd reccomend a full overhaul, and probably a conversion to insert-type bearings by getting the rods machined to accept a removable bearing.
Jerry