Yeah, I saw that I could get a different differential. That brings me back to the gearing, though, right? I'd have to make sure I had the same gearing as the one that comes out so it matches still with the front, wouldn't I? On Rockauto.com I didn't see that gearing was a point of selection for the parts, so I didn't understand that, either.
I'm going to have to do a lot of study first before I am going to be confident in pulling off the differential swap-out. My mind is always three repairs ahead of my budget and shop time.
Mostly, this all started earlier today when I was looking at a truck to buy for snow plowing, and I noticed what looked like oil all over the pumpkin. And the cover was all rusty, and there was a drop of oil at the bottom of the cover waiting to fall. So I looked at a different truck and it didn't look like that, and then I looked at my TB, and not only did my TB not look like that, I realized I didn't know as much about differentials as I probably ought to if I thought I was going to buy and run a plow truck through the winter.
As I looked at parts on-line to try to figure out what my financial exposure for the differential would be if it failed (or was obviously crap and that's why the truck was so attractively priced) I kept realizing I still had more to learn.
AND THEN when I went to look for internet forums for that vehicle type, it became clear that GMTNation is a rarity among forums. Not much of a community out there on other platforms, that I could see. Maybe I just didn't hit the right ones, I don't know.