cam wont fit

You don't want to use any abrasive on a bearing surface. As they remove material, the abrasive (stone, sand, skotchbrite, etc) always sheds some of itself. On a bearing, this will imbed and come out later when it get's the chance. You want to shave or cut off bearing material. Not use an abrasive. Not to mention, on cam bearings, that abrasive will get into the oil passsages to the main bearings. Bad news.