hmm btw, an Y connection of brass would be perfect for paralell channeling radiators, if you run 3/8 hose, use 5/8 Y-conenctor. preferably u use something like an Eheim 1250 (the big momma of ALL inline pumps).
then we are talking about something like 1000gph through waterblock... or uh that wouldnt go but some 400gph.
using a waterblock like this
http://www.swoc.dns2go.com/tanka/h2o/vattenblock.jpg
http://www.swoc.dns2go.com/tanka/h2o/vattenblock_2.jpg
(not finished yet)
would certainly do its job of removing heat.
and then having 200gph through the rads wouldnt be bad either... right?