Remove all burrs from the crankshaft oil holes using a stone, file, or scraper to ensure the oil holes are chamfered, preventing sharp edges from gouging or scratching the new bearings. Clean the crankshaft with solvent and dry it with compressed air if available, ensuring to clean the oil holes with a stiff brush and flush them with solvent. Check the main and connecting rod bearing journals for uneven wear, scoring, pits, and cracks. Rub a penny across each journal several times; if copper rubs off and embeds in the crankshaft, the journals should be reground. Inspect the rest of the crankshaft for cracks and other damage, using magnaflux to reveal hidden cracks, which an automotive machine shop can handle. Measure the diameter of the main and connecting rod journals with a micrometer, comparing results at several points to detect taper and out-of-round conditions, taking measurements at each end of the journal near the crank throws. If the crankshaft journals are damaged, tapered, out-of-round, or worn beyond specified limits, have the crankshaft re-ground by an automotive machine shop, ensuring the correct size bearing inserts are used if reconditioned. Check the oil seal journals at each end of the crankshaft for wear and damage; if grooves, nicks, or scratches are present, the new seal may leak upon reassembly. An automotive machine shop may repair the journal by pressing on a thin sleeve, but if repair isn't feasible, a new or different crankshaft should be installed. Finally, examine the main and rod bearing inserts.