Using solvent clean the crankshaft and if possible air dry it, always ensure that the holes are brushed with stiff brush and flushed with solvent. Using a thread mike or feeler gauge, measure the journal diameters of all main and connecting rod bearings for amount of ovality or taper and look for signs of scoring, pits or cracks, etc. Examine the rest of the crankshaft for any cracks or other damage. Use a micrometer to take the actual measurements of the diameter of the main and connecting rod journals and compare the same with the standard dimensions where by taking measurements at different positions around the circumference of each journal in order to check for taper or being out of round. Further, also take measurements at each end of the journal, at a plane perpendicular to the crank throw to detect taper. If the journals are badly scored, undersized, oval or excessively worn, have the crankshaft reconditioned by an automotive machine shop and, if reconditioning is done, use the correct size bearing inserts. Last but not the least, check on the main and the rod bearing inserts.