On a '58 235, my pan has a very small hole (maybe 1/8 inch or smaller) located in the right front attachment flange. It appears to belong there, and is open to the inner part of the pan.

The engine is a new rebuild, and running well, but I notice that there is a very slight amount of oil escaping from that hole. I suspect that it is to assure that there is not excessive oil in the crankcase, but...I'm not sure. Can anyone shed a little light on my confusion?

Thanks