i want to buy a civic type R camshaft and really want to get the real one, they said that you can look at the key location on the distributor side, you ought to see two engrave rings intake and one at the exhaust, my question is, how do i know that its the real thing? some says its easy to make it fake by sending it to machine shops and put engrave rings just like the real one. what are other factors that you can consider that its the real type R camshaft?