For what it's worth, here's the dimensions of my 95 E350 (4 windows):
Usable Bus Interior Dimensions (behind the driver's seat):
- Length: 10 feet
- Width: 6.5 feet
- Height: 5.5 feet
Window Dimensions:
- Width: 25 inches
- Height: 26 inches
- Space in between the windows: 1.25 inches
Exterior Bus Dimensions:
- Length: 19.5 feet bumper to bumper
- Length (between axles): 11.5 feet
- Width: 6.5 feet (7.5 feet with the mirrors)
- Height: 8 feet