The valves RARELY, if ever stick open to where a tear down is necessary. Again, I've never seen the problems where a vacuum repair didnt take care of it. If the shafts are carboned up, Seafoam or comparable fuel system cleanings will clear the crud. I don't have access to AllData today, but you might check under your hood for a vacuum routing diagram. I work on county vehicles that have 4.6 and 5.4L engines, so I can't tell you on a V-6. I will see if I can talk my neighbor into popping his hood on his V-6 when I get home and see what I can find.