Electric fan install
There's a good gap between the fan and radiator, but there are oil cooler lines that cross in the path between them.
Ok, sorry for the delay but my phone wouldn't let me reply properly while I was out. Here is the install thread for a Ford Windstar fan into a CUCV.
http://ck5.com/forums/threads/dual-circuit-windstar-fan-final-shroud-update-05-11-11.267400/
There is enough room once the original fan and shroud are removed to install two of these fans. Clearance between the radiator, oil lines included is more than enough.
Here is the electric fan install kit I used. The parts store will ask you what temperature want for the thermostat switch. I would go with one that is slightly above your thermostat temperature. That way the fan is not on unnecessarily on all the time. It will only come on once the truck starts to actually get hot.
There has been much debate over whether or not this will save gas mileage because the increased load on the alternator will also reduce gas mileage. My take is that fan clutch or not, that belt driven fan is turning all the time. This kit will only turn on the fan when the truck actually needs it. The rest of the time, it is completely unecessary. By the way, the CFM on that Ford Windstar is higher than all but the most expensive $500 + Flex-a-lite or BeCool fans.
As suggested, If you are doing river crossings, I would install a switch to kill power so the fan is not turning when you hit water. Assuming you remember to flip it.
Good luck
One more thing, as I was tackling my cooling system I ran a radiator flush through it. It removed enough crud that a hole was revealed 4 inches above the bottom of the radiator. This means that over the existence of this truck, there was more than 4 inches of crud lying in the bottom of the radiator. If you are having any cooling issues, I would have this checked out. If your radiator is not at top efficiency, everything runs hotter since Oil, Trans, and water are running through it.