Hi, i havent had much luck finding any info on moving the radiator behind the front seats, like an ultra 4 car or rainforest challege truck do. I am not sure if that kind of modification has a name or not, which may be why i havent had any luck searching. I have a sami with an 8v kick swapped in. I dont think the factory water pump could move the extra coolant, and futher what size of hose or tube to use.

i see no reason the waterpump wouldn't work, if you are not changing the relative elevation of the radiator. the pump wouldn't know the difference. also delivery sizes shouldn't change.
+ extra coolant is good.
i have a lotus- mid engine w/radiator in front, 1 1/4" tubes, very conventional waterpump........ takes a bit longer to warm that much liquid, but that's what the thermostat is for.
just my thoughts.
fording? or mud womping?

Okay cool! I cant think if the back seats floor is lower or higher than the factory location, but i will check today when i throw together the rest of new harness. I wanted to move the rad back for a number of reasons, the rad wont get clogged with mud or punctured by sticks, allows me to mount the winch and barwork closer for a better approach angle, cover the belts with something more solid, and more coolant too, like you said.
I was just going to use the same radiator i already have, a stock 1.3 or 1.6 8v (i dunno, i didn't do the swap) The rig never got too hot, but it is plastic, should i worry about it failing on me, only a few feet away from my seat?
I am building this to be able to float a river if i wanted, not that it will happen much.

it would be an interesting mod.
i was satisfied w/how close i could mount my winch(cut out some body in front of the radiator), and screened what seemed exposed, 'cause i nose thru brush a lot.

take some pics as you progress.........