Tighten until they bottom out. The mounts are designed to be assembled that way. Use new bolts and those prevailing torque lock nuts. 

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Mark McCulley
Sent: Saturday, August 31, 2013 2:29 PM
To: vanagon@GERRY.VANAGON.COM
Subject: syncro front diff mount replacement

Hi Folks,

I'm replacing the 3 mounts on my syncro's front diff and wondering how much to tighten the mount bolts. It seems if I tighten too much it will reduce the capability of the mounts to absorb vibration. Too little and the mounts can move around on the frame. Can anyone provide some guidance?

-Mark
'87 Syncro Westfalia