Were you able to get the gears into the NV4500 and the NV4500 into the Suburban?
The pilot bearing in my wagon bit the dust a few weeks ago, so I went ahead and swapped the NV4500 in while I had the NV3500 out.
As part of that process, I put an aftermarket "early" fifth gear set into my "late" NV4500 before I installed it. So, if you haven't done that gear swap yet, I can now officially confirm that it works.
I've driven it with the 0.643 NV4500 a few times now and it seems to work great. I guess I need to update the thread on my wagon eventually...
-Funkhoss