The profile looks better, but you can use the "bio" section to describe your truck a bit for everyone. This way, everyone has an idea of what you are asking about. /forums/images/icons/wink.gif
As for your xfer case, does the drive shaft "slip" into it? If so, that is a slip yoke. I'm guessing that you have a slip yoke, so as Hossbaby and I said, pull the shaft, pull the seal, replace the seal. And YES, a little RTV will help seal up the scratches you put in the tail shaft with the screw drivers that you will use to pull that seal. Finally, it is a bright idea to also lube up the output shaft with some lithium grease before installing it. GMs are FAMOUS for their rear drive shafts binding, causing a thumping or banging noise when unloading the pressure applied upon braking.
Hope this helps!
-Dan