I got a call from napa telling me that my cylinder head is finished.they plained it down and did a valve job.He told me that it was gumed up.i asked him why does he think that was,and he asked me if it sat for a while,and i said no.I told him i've used this stuff called restore,and seafoam.he told me that neither of that would do that.it has sat for as long as a week.now since hes not a supra lover like we are i thought some of you experts might maybe know why it was gummed up.Thanks for any responce.