I believe they do. You just have to watch out for newer trucks like above 89 some of the steering boxes are metric fittings.?
I looked at my steering box and walked around the junkyard, found a 2wd version that looked the same out of a 77 or 79 chevy truck. It swapped right in, the only thing that was not the same was the rag joint.
The rag joint diameter where it bolts onto the splines of the steering box are bigger for the 4wd and smaller on a 2wd box. Be sure you grab a 2wd rag joint with the steering box so everything bolts right up.