Each fan weighs 5.5 lbs., with the total assy of 2 fans and shroud weighing 13 lbs.
BTW, it looks like 2 12" fans would be the most we could fit behind our radiators. However, I did find these fans that flow some serious air:
http://www.alamomotorsports.com/pmc/Cat_page16.html . Check out the 14" & 16" versions. Just one of these would do quite well I would think. Possibly use one of them as a puller and then mount a 10" pusher on the front of my oil cooler and I would expect my situation would be well improved.