In the article Dustin linked:
"The two Sure Grip types can be interchanged between the carriers if the matching differential axle bearings are retained. The outside diameter of the cups are the same between the '741'/'742' and the '489'; the inner cone differs. "
So what I'm drawing from that is as long as I keep hold of the bearings I can swap the different diffs. My question is, what about the different pinions? Like the carrier bearings, can they too be swapped? That part is still unclear