I got my rebuilt head back from the machine shop. They did not install the rocker arms nor the valve stem seals. I have never done this before so I am following steps in the haynes manual. Got it all figured out but it didnt say anything about these valve stem seals. These are the little black caps right???? If i put them ontop of the valve stem then the rocker arm ontop of that it doesnt seem to sit or fit properly. is this normal??