Well, I pulled the passenger side valve cover off today (not sure why) and noticed that #1 and #3 rocker arms were VERY loose! They were so loose I could lift the rocker up about 1/4 inch off the stud. I know they naturally are supposed to be a little loose when the valve is closed but I don't think they are supposed to be THAT loose....are they? Apparently, I've been mistaking the rocker noise as a header leak. Could this be the cause of the drop in oil pressure or did I just discover another problem that need fixed now?