Note that I'm still having marginal oil temps in hot weather while only producing around 120 HP NA at only 5200 RPM. So I'm amazed when others producing much more power are able to keep oil temp below 210 with just a single Mazda oil cooler.

 Thanks for the great info Perry.  Reports like this are why I went with the evap core, rather than the stock 2nd gen cooler that I have sitting at the hanger.  With the B drive, at 5200 rpm in climb, I never exceeded 200 degrees, so it was working well.  Now, with the C drive, climbing in the low 6000 range, I'm overheating some.  Of course it's also 90+ degrees outside.  Hopefully, I can tweak the airflow a bit, and perhaps accept a little higher temp for occasional climbs, and be happy with what I have.