I did a search in the newb section, and the search thing didnt' come up with the answer I was looking for. What is the difference between the two?? I thought there wasn't anything, but was on the phone ordering some parts, and the guy said there was a difference. This is for a 62' 4wd suburban that I'm putting power steering on to. I have the 4wd box, and there is a kit that Chevy Duty sells for $60 that says for 2wd ONLY. When I called them, the guy didn't know, he was just going by what the kit says. I thought the only difference was the output shaft, and that the boxes will bolt on between 2wd and 4wd frames. So, can someone enlighten me and verify that the boxes are the same, just the shaft is different??