need to know which one sends and which one is return. I assume top sends and bottom returns, sicne it doesn't make much sense to try and push the fluid upward.

Am I right?

 

top line sends it back to the tranny i believe (line with the clamp, before metal line).....

i couldnt see running fluid from the cooler back into the hot radiator

 

the radiator isn't that hot compared to the trans temps. besides, cold fluid is as bad as hot. typically, you install the cooler inline before the radiator trans cooler. That way it cools, then stabilizes the temps.

 

When I installed my aux ATF cooler, I was told by a trans shop locally it was the upper line to tap into as it's the return to the unit on this trans.

Hope that helps...

 

http://www.fbody.com/tech/details.cgi?id=31

This is a good install guide....however, I installed mine a little different. I put my lines in a differnt location that made it look stock, through the metal frame under the radiator and out the passenger side next to the radiator(no need to drill holes in your air damn). this also tells you which one is which