Has anyone considered replacing the bushings that support the transmission
and front differential / VC.  If these bushings wear out over time they
might affect the alignment of the running gear or deformed under specific
load conditions resulting in a vibration of the drive shaft.  Let me know
this makes any sense or anyone has the success in correcting this type of
vibration.  I haven't 86 syncro that vibrates at around 50 60 but goes away
above 60 miles an hour.  I've not yet done anything to try to resolve this
problem.

Derrek