used cooler....
Beware. Why are they selling the cooler? Because the engine failed, and there are little pieces of material in the cooler that will not come out. Any used cooler should be cleaned, and Pacific Oil Coolers is one of the few FAA certified places that can do it correctly. Just cleaning one out with the car wash sprayer won't work. They charge about 100 bucks to clean one.
I can't see cutting corners on a used cooler. How much do you spend on the engine? Buy a new one. I use Fluidyne coolers. Not cheap. But far better than any others I've seen. Of course it was 106 at my house yesterday. So, I need a serious cooler.
Previously, on my 351C car, I ran an earls cooler AND an in-radiator heat exchanger built in to my Ron Davis radiator. I saw no reduction in oil temps. Saw up to 30 degrees with the Flyuidyne DB600. It was the largest cooler I could find. parked it right in front of the radiator, with a small gap. Works good.
Dan