What are the consequences if I were to put the cooler in the feed line from the transmission to the radiator, instead of the return line ?

I live in San Diego and temperature rarely drops below 32 degrees F in the winter and hardly see above 90 F in the summer.

Thanks

 

It may reduce your a/t fluid cooling. The radiator will probably operate at 220deg. so you may end up warming the a/t fluid in the radiator after you cool it in the a/t cooler.