OK
You, do some homework. 1, Is the transmission aircooled only, watercooled only or both?
2, For now forget the cooler and run the heater hoses like any other Ford Yblock.
3, After you figure out the heater hose routing THEN ADD THE COOLER. It is non directional, water can flow either way and still cool the ATF INSIDE THE COOLER.
4, The right way is to get a radiator with a cooler or a stand alone AT cooler IN THE AIRSTREAM, but you already know that.
5, With that mickey-mouse cooler you have you won`t save anything.