I just checked my intake and exhaust valves today. The intakes are .004 and I'm happy with that, but all of the exhausts range from .004 to .006 and that's not what they're suppossed to be. The car runs great so what is the harm if I leave them the way they are? I couldn't get a wrench on them to make the needed adjustments. Any recommendations?? Car has 177K on it and I don't know it's maint. history.