There is a rule saying oil cooler "scoop" cannot extend below the bumper. This is about 2" below the bottom of the frame horns on my car.
Obviously, if you use the scoops I've seen, with their upward slope on the bottom surface, the oil cooler fins would be a little higher and perhaps the fittings or mountings might be at the 2" below level.
There is a tubular guard that protects the steering gear, among other functions it serves. It is 4" below the bottom of the frame horn.
What is the lowest point that you would think is best for the lowest part of the oil cooler, including mounting brackets and fittings? Assume no scoop.
Your opinions and experience are appreciated.