Do you get the vibration form the engine or while you are driving?  May be a 
bad CV joint.  I've seen them cause vibrations that appear engine related.

Dennis

-----Original Message-----
>From:	vanagon@lenti.med.umn.edu  On Behalf Of mark keller
Sent:	Friday, August 08, 1997 1:27 PM
To:	Multiple recipients of list
Subject:	Bad vibrations

>Date: Fri, 8 Aug 1997 10:50:09 -0500
>Reply-To: wilpho@mcn.net
>Originator: vanagon@lenti.med.umn.edu
>Sender: vanagon@lenti.med.umn.edu
>Precedence: none
>From: rob wilke <wilpho@mcn.net>
>To: Multiple recipients of list <vanagon@lenti.med.umn.edu>
>Subject: Bad vibrations
>
>My 87 syncro has this strange vibration that comes and goes. My mechanic
>is an excellent and honest one. the best explanation  he's found so far
>is the fan belts seem to jump around alot like 1/2 inch or so when you
>rev the engine up. It seems like a weird harmonic distortion thing??Open
>for suggestions...........btw the drive shaft is out , we thought it was
>the problembut it still has this vibration....
>
>Rob Wilke
>87 Syncro
>78 & 77 saab
>49 Chevy Pickup
>