IMG_0224 by
Steve Stewart, on Flickr
2017 Transit Quigley 4x4 HR LWB. Ecoboost and 3.31 Ltd Slip. Couldn't be happier. The lift from Quigley is 2". I was, with one beer, one hour, and a grinder, able to fit 235/85/16s underneath with no rubbing. My Ford dealer says that tire size doesn't affect warranty. However, Quigley says that if a front hub fails and the van has bigger than 245/75/16 or more than X amount of rim offset( sorry don't remember that), Quigley won't cover the hub under warranty.
I have 8000 miles on mine so far. 15.6mpg average. Way more power than the 5.4. Or maybe it just feels like it since the 4x4 Transit is a solid 2500 pounds lighter than the E350 SMB? The six-speed automatic feels great. True mechanical 2-speed transfer case. Traditional mechanical shifter inside, with automatic-locking hubs. Can shift into 4-High while driving.
I'm not a serious off roader, but I camp in my van off-road 3-4 days/week all year long. Think of it like you would a stock club cab f150 4x4 with a limited slip. It will be comparable to that off-road - meaning if you're not a serious off-roader it will be just fine. If you were climbing a lot of rock slabs the front overhang might be an issue.