I checked my service book and cd and could not determine an answer so here goes...which tranny cooler line on my radiator is the supply line and which is the return...i think the top line is supply and the bottom is return as it would make most sense to let gravity work to get the cooled fluid back to the tranny but i want to be certain...any help is appreciated..thanks!

 

Yours should be like mine. The line going to the top right side of the rad is coming from the transmission. It exits the bottom of the rad and goes to the factory transmission cooler on the lower left hand side in front of the rad (unless you have already replaced that as I have). Then it goes from the cooler back to the transmission. The hard lines coming and going from the transmission are 5/16" up until the bottom of the rad where the hard lines turn into a 6" rubber line and back to a hard line. At that point they switch from 5/16" to 3/8".