Hey 4.3,
I took pictures and drawings with bolt hole counts and measurements to my local BIG truck junk yard and they knew exactly what I had and pulled the pumpkin right off the rack. I don't know what years are interchangable, but would guess there are many. You more than likely have a GM rear on your truck and your available ratios with that are very limited.
I still think swapping in a complete Eaton 2-speed with the right gears would give the same results as putting in a Brownie Aux Trans for a lot less money. Just need to get the same wheel lug patteren.
Mike
