In regards to hot oil and how it plays havoc with your oil, I went to Hayden's website to see what they offered for oil coolers... By the way, they have just about everything one could look for.
Here is what they say about oil temp and mileage. Now this is for a water cooled motor, but I'm sure the same is true for air cooled, if not more so. ...
Then again, they are selling oil coolers so of course will also think of them as essential [cynic? me? ]
PS: I was going to say "nice Willys" but suspect that could be misconstrued!