It's a wise idea to establish a good relationship with a machine shop. That way you'll have access to experts for advice and guidance once you start tearing down the engine and inspecting the internals. JMS' Freddy Hernandez showed us a cool tip: Check the height of the valve stems with a straight edge. "The valves should all be at the same height. You can tell if the valves and seats are hammered if any are sticking up higher than the others."