Update: Pressure testing the cooler showed air bubbles escaping from a crack at the end of the first row of fins, on the opposite side of the inlet tube flange. It is possible I inadvertently damaged the cooler during the installation. Regardless, I no longer want a drawn cup style oil cooler in my airplane, as they are much too delicate. After talking with an Aero-Classics engineer about the possibilities and performance of a couple of coolers, I decided to order a 8001649. It was quite expensive, but I feel much better having a welded bar-and-plate oil cooler in my airplane. The engineer assured me this cooler will be as efficient, or better than the Airflow-Systems cooler, and it will be much more robust.