I'd run them & enjoy being under driven... sorry I missed your other thread, need to add Vitara to you topics for it to get noticed by the right people. I thought it was another one of those can I fit 31's to my sierra thread with no lift & will low range be ok for rock crawling.
http://auszookers.com/index.php?name=Fo ... ic&t=25439
The GV gears will be a ratio very similar to what you already have, you want a front & rear set of 5.12's from a Vitara.
The rear will bolt straight in, they come in 2 different crown wheel configurations 10 & 12 bolt, both will bolt straight in with no problems... just remember what you've fitted if you want to install a locker later down the track.
The front also comes in 2 configurations, 22 & 26 spline, your CV's will be 26 spline. If you score a 22 spline front, when getting the steel front diff built, get your 26 spline hemisphere fitted to the 5.12 crownwheel & have the 5.12 R&P fitted to your GV steel diff.