81 k10 12 bolt differential rebuild

[juiceboxhero]

Hello all,
During my drive home yesterday i heard a slight clicking sound. So i decided to pull the diff cover off and this is what happened. It looks like ill have to have a complete overhaul on the diff. My main question on this is has anyone ever gone from what i assume is a series 2 diff to a 3 or 4 and what issues they had? And also since it being 4x4 the front is a corp 10 bolt, i would have to change out the front set of gears as well.
It seems i have a 41/16 gear set (2.56).
Any advise would be appreciated