Let me tell you a little story....the story of Slo T3g and his ticking b18 head. (should be some music here, right?)...any way... when we took the valve cover off one of the tappet lock nuts had come completely off. We retrieved the wayward nut and reinstalled same. But it still ticked like hell. But that's because ol' Slo T3g (who is much smarter than his Urdaddi) didn't have the "feel" for adjusting those valves and they was alllllll loose (better than tight!). Proper adjustment= no mo' ticking b18 head.