PU Truck mag That answered a lot of my questions about these covers. Extra large ones may not make a lot of sense because they disturb the oil flow in the housing.
Yes Banks did a lot of work on those videos to gives us the facts. I’m waiting for his Dyno testing to see what the temps do. I went with the Ford Factory finned aluminum cover. $55 is way less than the aftermarket ones that create issues. I especially liked the one where he put the plexiglass cover on the aftermarket diff cover!