synthetic gear oil question HELP

["PAT MARTIN" <MARDKINS@msn.com>]

I recently purchase some redline 75w90 gear oil for my 4000q.  I was reading 
the tag and it said that "This product not designed for most manual 
transmissions since the extreme slipperiness may cause gear clash".  Since the 
car came with synthetic is this one of the few that can take this product or 
is there another synthetic gear oil that is just for man. transmissions.  I 
need to know soon because a friend is putting it in this AM.  
Pat Martin
864000csq  2 1/2 cat back, H&R-Boge,advanced and loving it.  Drilled and 
stopping it.  Koenig Cobra 16x7 with AVS Intermediates, cheap Kelly 
Springfield snows now, K&N. 
95 subaru legacy 
Bothell, Wa.