DO NOT try to use the transmission cooler part of the radiator as an engine oil cooler! There's a lot more pressure in the oil system, especially at start up than there is in the transmission of an automatic in the cooling loop. Think about how we have braided steel lines made up for oil coolers, and then look at the lines that connect an automatic transmission oil cooler with just rubber hose and simple clamps. If that pressure breaks the inside part of your automatic transmission cooler that is in the radiator - look out. That's the sense I make of it.

John B.