When the rules call for a "bone stock" crankshaft, go with Crower's Pure-Stock. Factory GM forging made form S38 micro alloy. Pure-Stock means just that. No lightening holes, OD triming, or any other lightening features that woul jeopardize "stock" status. Crower race prepping includes 1/8" radii and Crower heat-treat for added strength (same heat treat used on their 4340 cranks). Other Crower features include thorough magna-flux inspection, chamfered oil holes, end-to-end index check and polish.