Frame rot around the steering box on all the early 90s and newer B vans is a concern. There are no parts (patch panels) available to fix the area, and there are a lot of compound curves. It is a major pain to repair the area around the steering box. The frame of any B van in the rust belt (or near it) is susceptible to the rust near the steering box.

I would go at both van frames with a welders pick and be sure the frame structure is still good before I would even consider what you are looking at doing. The frame there should be at least 1/8" steel, you can hit that pretty hard with a sharp point and a pretty hard swing of the welders pick hammer and do nothing but a possible small dent. If the pick blows through at all, the frame is too weak for the van to be driven on the street. Gene