Good grief. That’s more than I thought and doesn’t look like it’s a fun install either.
$200 later I bought the adapter off of ebay. Thanks @sweetk30. Now to source the gaskets and time. I'm contemplating also having the t-case rebuilt while it's out and possibly the transmission to. Can't imagine all of that black sludge I keep finding at the bottom of the transmission pan is good. Since I'm yanking everything anyways and need new driveshafts, now is the time to decide if I want to go ahead and convert to an auto with OD or not.
4.88's and 37's. 3500rpm at 70 isn't cool for me and our toll roads are 80mph which is 4000rpm haha. Currently I'm running a TH350.

I'm still up in the air. I got some folks saying it's fine and others saying go 4l80e. I've got time. Progress is going to slow up next year because I spent way to much money this year on this truck.
Auto's don't scare me. Not worried about that. And definitely not worried about blowing up a 4l80e.