Well, the title says it all. I got a 2WD tranny and I need a 4WD. I just got a complete Chevy NV3500 that I plan on swapping the tailhousings with, now from what I can figure I still need to either swap the main shaft with a 4WD main shaft or have my 2WD main shaft machined down. I have a few other ideas, but they are a little too much labor I think, like using the existing tranny and creating a divorced transfer case. too much? I don't know.