I know why it is there on my auto trans 300d's, to smoothen out the shifts. But why on a manual transmission. I changed the trans vac valve leaver then thought ,why on a manual trans. Can it be eliminated. then plug the series of vacuum lines that lead to the thermo vacuum valve, switchover valve,and EGR valve. Can i just plug the line to the series i mentioned and leave the 3/2 vacuum valve. A lot of questions to have on one thread. Thanks RAY M