These fit the A-65 through O-200 models. They mount on the right side of the case next to the oil pressure regulator. You simply remove the oil bypass cover and install the cooler on the studs that used to attach the cover. They are fairly rare.
Hmmm. I know somebody with an O-200 that might be really interested in that kind of part. The fellow has a beautiful Q-200 but has struggled with oil cooler installation behind #4 (lyc numbering) due to limited space. He has busted oil fittings in flight twice.
