Need input on running trans cooler lines

[ZEKE68]

Next to the last problem I have to solve on my rebuild is running new transmission cooler lines. Planning on running an air cooler in parallel with the radiator cooler and teeing in the front to each. The reason I am running parallel is because the radiator cooler is 5/16" line and the transmission is supposed to be 3/8" and in parallel I will maintain the higher flow . Any ways I have been back and forth about where to run to run the lines, 1. up by the oil pan like the factory did it and having flex lines in the front, or 2. running down the frame rails and putting flex lines from the transmission over to the frame, in which case I will have to fab up a heat shield above the exhaust to protect the flex lines. Looking for some comments from experience to get me off the fence. Sorry for the long post.