Ran out of time yesterday and had to put it all back together, but will be checking gear ratios front and back as this was the only remaining possibilty my mechanic and I could think of, he does not suspect the CV's since everything is nice and tight up there, tie rods, etc. It's not a huge issue just now since I don't use 4wd much, but will get it taken care of before winter. Really needed it in the snow and doesn't help to wrestle the steering just have traction. I'm considering which gear to change if it turns out to be different, if one is 4.3 might stick with it and replace the other, but no higher as I'm never going to lift much, would stick to 4.1 if so.

I have a friend in the VA4ROC with an 88 and he can drive fast in 4wd, Owners manual also specifies top speeds in 2wd and 4wd Hi match, up to 90ish in 5th - Impossible right now for my truck so something is definitely not right. ALso my 86 didn't do this, I could drive it pretty fast in 4wd and never feel anything until turning, then it was still not close to this jerking. Only some loss of power, this is Biiig power loss.
I took pics, they will be posted here when developed.