ghittner

My bet is that you're running way lean, did you check plugs or do you run an afr gauge?

blue thunder

What is the oil pressure in the engine that runs hot BBB vs the one that does not? Something I have noticed as I have battle oil temp problems for years, how the engine is built makes a large difference in oil temps. Clearances wise that is. That's why I ask about oil pressure. If your pressure is high you may get an oil temp benefit by lowering the viscosity of the motor oil you use.

Also, I would try lowering the oil level by a couple quarts as a test. 16 qt gives you lots of room to lower the level. I'd try 10 just to see if it changes temps dramatically.