Gus, I was instructed by Coan transmissions to go through the engine radiator to raise the trans temp to engine temp, then go through an auxilliary cooler.
ONLY exception is a thremo controlled flow valve inline to keep the oil circulating through the trans until temp is up, or a summer only vehicle (like the Vette is) where temps would reach operating temp quicker.
Any source for the valve?





Your Sub looks awesome! 
Just need to figure out all the other things to make the swap work.