When all of our kids were still home and camping with us, I towed a 33' travel trailer with a 1 ton Ford E350 12 passenger van. Plenty of room for the kids, plenty of payload capacity, plenty of storage space. It worked great for us, and handled the trailer like a champ. My van had the 6.8L V10 gas engine, but as you noted they made them with a diesel. I love trucks and actually am back in one now as we no longer need the van, but I don't know why more folks with large families don't tow with them, especially when compared with SUVs. I think a lot of people get hung up on the image of vans compared to SUVs, but in many cases vans are much more capable family haulers and tow vehicles. Not to mention they tend to run significantly cheaper than trucks and SUVs on the used vehicle market.