Wesley,
I want you to fly your airplane and get the oil temperatures up to normal operating temperatures.
Then set up for normal cruise power settings.
Write down the outside air temperature, and the oil temperature.
Based on your description, it seems as though you’re basing your high oil temp conclusions based on ground running.
Ground running is not what airplanes are made for.
Knowing these engines are made to operated in a dynamic atmosphere that takes place while flying, I plan my flights to minimize ground running.
There’s no where near enough cooling ram air delivered to either the cylinders or the oil cooler during ground running.
If you’re worried about anything with the engine, it’s perfectly acceptable to conduct this test flight over head above your airport.
After the flight, please let me know what your oil temperatures are after a stabilized cruise at your normal cruise power settings.
One other suggestion; try a different oil. Most of the flyers around here are having good luck with Phillips Victory oil. You can put in the multi-grade but I suggest using the straight 100 oil first.
Best,
Steve