The factory AWD 1500 vans can easily fit a 31 with any of the 2" lift kits you can find by poking around on the internet. Boulder Offroad sells them as one option. Good friend of mine has one with that kit and runs a 265x70x17 with no problem.
If you can find one with the G80 rear locker they are a solid performer out of the box. Its not going to be a rock crawler or anything but really good in snow, loose dirt, mud etc.
2015 Chevy Express 3500 Duramax
w/ Quigley 4x4 & Agile Fox shocks
Sold 2005 E350 Chateau
Quigley with Agile RIP, 6.0 PSD