changing out your front diff for another

has anyone tried to put a selectable locker in the front of their silverado? i'm trying to come up with an idea to sacrifice some cushy ride for some off-road capibility. here's my idea: take a center section out of whatever, we'll say a dana 44, use the idea of the original front diff and fab up some small axle shafts with the spline matching whatever selectable diff you decide to use. so the shafts would consist of a stub with splines on one end and a drive flange on the other end, then drive flange, universal joint, slip yoke style shaft, another u-joint, followed by another small stub shaft that would match the spline count of the wheel hub. now with a selectable diff, would it be "open" in the unlocked position? i realize that with u-joints instead of cv joints, the wheels will "jump" when you turn, but is this only true if you lock the front in? just wondering what ppl think of this idea.

From what I have read on other forums, some have swaped over to a 3/4 ton front diff, that is big enough you can put a locker in it. Its not easy though, many parts need to be fabbed up. here is a good thread on that http://www.gmfullsize.com/forum/showthread.php?t=64681