Remove all burrs from the crankshaft oil holes with a stone, file, or scraper to ensure sharp edges don't gouge or scratch the new bearings. Clean the crankshaft with solvent and dry it with compressed air if available. 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, indicating roughness. Inspect the rest of the crankshaft for cracks and other damage, and have it magnafluxed to reveal hidden cracks at an automotive machine shop. 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. If the journals are damaged, tapered, out-of-round, or worn beyond limits, have the crankshaft reground 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, new seals 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.