I wasn't sure where to put this, category-wise, but I just need a little help figuring out how to run my transmission cooling lines.

On a TH-350, there's an "upper" and "lower" flare fitting for the transmission cooling lines. Does anyone know which fitting goes to cooler and which comes to transmission? It is a stupid question, I know, but I am not sure how else to figure it out.

The only book I have on the 350 and simply says is that there are "two connections for the transmission cooling lines".

 

the 71 Oldsmobile Service Manual has the flow going from the transmission to the lower side of the cooler and from the top side of the cooler back to the transmission.