Drum Drilling

I have heard of alot of people doing this and no one here has any advice o. It at all? Also I have seen people take small bolt 4 piston disk brakes and drill them for large bolt. Actually a guy at the spring fling in van nuys had them for sale. Stupid me though I didn't think to ask where he got it done and now I am stuck calling machine shops and having people tell me they have no idea what I am talking about. So done has got to have more Information



Jeff