I know the LS can get ragged on, but I am very proud to say mine has been 100% solid for me. Other than the aforementioned spark plugs, the engine is as it came from the factory. Nothing on it has ever been opened up (valve covers, manifold, etc). Just regular maintenance (plugs, oil, filters, coolant, etc) for 15+ years and 190,000+ miles. Not even an oil additive. For the first year of having AFM/DoD I think that is pretty damn good.