Mobil Synthetic Gear Oil

[Chuck Stiehm <cstiehm@netcomsol.com>]

Does anyone have any info on whether it is good, bad, or ugly to replace 
the drivesshaft and rear end with Mobil Synthetic?  I was planning on doing 
this but a coworker said that my seals would leak if I went to a synthetic 
now.  Any limited slip additive required?

I just picked up valve cover gaskets ($39 at dealer) and a rear diff gasket 
and was planning on draining the rear diff and have already bought the 
Mobil Synthetic.

Much Appreciated,
Chuck
Sy 2337
Sterling, VA