Can anyone tell me which line out of the transmission is the input to the cooler? I have a 93 D250 Ram CTD with standard 4 speed/over-dirve and factory installed 2nd cooler under the bed. Sorry guys, I haven't got the shop manual yet. A picture would be great. I want to put the trans temp gage sensor in that line. Also, is a brass tee allright or should I try to find a steel fitting? I haven't crawled under yet but I though I would save a trip and ask first.