Trans Cooler

I am putting a transmission fluid cooler on my 2001 Grand Prix (3800 Series II) and was wondering if anyone knows which line in the radiator is the return line to the trans pan. Top or bottom of the radiator??

The bottom line should be the return. It really doesn't matter if you are disconnecting the in radiator cooler. The aftermarket cooler should work either way.

Thanks, I'll give that a shot.. I was actually planning on running it in series with the factory cooler though, as I hear that they are prertty inefficient.. No real need for one, but you know what they say about an ounce of prevention...
SAMSUNG-SGH-A867/A867UCHJ3 SHP/VPP/R5 NetFront/3.5 SMM-MMS/1.2.0 profile/MIDP-2.0 configuration/CLDC-1.1