I've fabricated the mounts for the radiator and fans, and it all worked out really well. The radiator is the biggest Griffin one I could fit between the modified chassis rails (I cut off and welded up the flange from the tops of them, to fit a bigger cross flow radiator). The dual fans are Spal high output 12", and the whole unit with the shroud fitted the radiator perfectly.
I riveted little plates with captive nuts onto the inside edge of the fan shroud...
...so you can bolt the mounts on to the shroud, which sandwiches the radiator with rubber lined clamps, keeping the radiator from touching any metal on the body in order to avoid electrolysis.
The whole unit is nice and rigid and bolts on via four 8mm bolts (there's captive nuts welded onto the inside of the clamps), making installation and removal real easy.