Power Steering Pump Cooler

Coolers were standard equipment when the car was equipped with the performance axle package.
3.54, 3.55, 3.91, 4.10 axle ratios.

Or as another poster replied, lots of times on fleet vehicles.
Fire dept. police department, heavy duty applications.

Those coolers alone, used, run lots of $$$$$$ to buy used, in this day and age.
They at one time were repoped, but only one run of them was ever produced, and that was it.
During the early part of this year, i sold one off that i had for decades, for two hundred bucks, and later found out that was cheap, with my price.