I can strongly recommend not to overfill Diesel engines with oil. "Engine oil" and "Diesel oil" are chemically rather similar. If the oil is sucked through your blowby system in a sharp curve due to overfilling, you may not be in a position to shut off your engine until the oil is finished and your engine is broken. It runs at full RPM's and the pistons are melting.
I have seen such engines, it is an ugly sight. Besides it is very dangerous for the driver, because he may loose control of the vehicle in the middle of a curve.