Most of the intrior trim will fit/work.
The windows however wil NOT fit. While the inner body panels are the same the outer body on window van curves in around the windows. Unless you want to do a bunch of paint and body work the factory windows cannot be done easily.
2008 Ford E-350 V-10 EB
U-Joint Off Road 4x4 kit in the garage
2004 F-350 Dana 60
I think it would be toooo much work/money to get the OE passenger windows in. As Ultrasport12 mentioned there are curves where the factory windows are recessed into.
there are plenty of RV type windows that would be way easier.
Here is a pretty bad pic of the factory curves:
2001 E350 PSD w/ a bunch of stuff.
And had three other E350s...