Technical 59a oil pan on an 8ba looks like this !!

trying to work out what is stopping the oil from coming out........

 

I don't believe they fit properly. Why are you using that pan on an 8BA? The center sump passenger car pan would be a better choice unless you need more clearance for steering components, etc. In that case a '48 to '52 truck pan is the one you need. You will also need the right oil pump pickup tube and screen for the pan you use. Your picture doesn't show enough of the thing to tell the problem..