Have one and want to install it. I know it needs to install in the return line and just want to make sure I have the right one. Looking at the two lines going into the radiator, I'm assuming it is the lower one, is this correct? The line leaves the radiator and into a small auxiliary cooler in front of the radiator and then back to the trans.

 

Correct.
1. the fluid leaves the front port on the transmission to the top of the radiator
2. leaves the bottom of the radiator to the driver's side cooler
3. leaves the passenger side cooler back to the rear inlet on the transmission.

I know you already did it but I hate seeing dozens of views and no responses....so here's one.