I don't have that Tool but a Induction Timing Light which I have would work. I went through the Plugs One at a Time. I found 2 Plugs #3 & #4 Cylinder that didn't look as clean as the Rest. I switched out those 2 Plugs and the Problem appears to be fixed. No more Vibration at high Idle and no Vibration when driving. Seems to be much more responsive too. So all my Time and Money spent looking for different Answers appears to have been fixed with $6.00 worth of 2 new Spark Plugs. If the Mechanic at the Shop I went to hadn't pointed out that there was a Vibration even at high Idle  without moving I would still be Scatching my Head. And that Advise was Free.

  

Mark, 
        Sometimes the most obvious thing is the hardest and last thing you look for. Glad it was so simple.



Frank/Rebop

Bristol, In ( by Elkhart) 

I got so focused on the fact that the Vibration was occurring while driving that I missed that it would do the same thing while in Neutral standing still. My Vacuum Gauge read 18 steady at Idle but the Plug breakdown was occurring at High idle Speed.  Sometimes a fresh set of Eyes helps. My initial thought was the Output Shaft Bushing on transmission because there is some Play but not enough I guess the cause the Vibration..Anyway glad I did figure out what the Problem was in the End.