I bought what I believed was a TW21 cam from a Ebay seller who swears its a new TW21 cam. It looks like a stock cam that was pulled from a stock TC88. Now I have never seen a stock cam because I have not opened my cam chest yet, how can I tell what cams I have? Identification marks etc...... Can anyone shed some light on how to identify a Harley stock cam from an andrews? Is there any distinctive markings? Any help would be appreciated?