How much should a valve adjustment job cost? I have 106K miles, I doubt they were ever adjusted, my millage performance is lower than spec but the engine runs strong, it's a mean Vehicross, and I love it. The gasket kit with gromets and spark plugs seals are about $70 online, about half factory or autozone type pricing; how much should labor cost for this job? How much does Isuzu dealer charge? Anybody know? THANKS!! Erik