I have the Ford 3:73s in my 91 and no whine at all. Got 4:10s in my 07 auto and there is a bit of whine at 50-60 mph range. Not extremly noticeable. Thinking about 4:56s in my 10' GT auto.
2012 Mustang GT Grabber Blue 6spd (Current)
1991 Mustang GT Ht Oxford White (Current)
1991 Mustang GT Conv Black
2000 Mustang GT HT Silver
2007 Mustang GT HT Tungsten Gray
2010 Mustang GT HT Black
2010 Challenger R/T Torred(Current)