Those that have Bob Helt's book... have now problem deciding which oils are correct. http://corvaircenter.com/phorum/file.php?1,file=57084,filename=oil-bobhelt.jpg And then the fact that our Valve springs only have 80 psi closed pressure pretty much negates the worry... Matt Nall Charleston, Oregon http://tinyurl.com/The-Patio http://tinyurl.com/Matts-Tech-Pages