I have overfilled my dry sump and it can have consequences, tank fills up and then oil started being thrown into the airbox. Normally as said you need space so best thing is to run it up to temperature with bonnet off, switch off and immediately check the level before all the oil leaves the tank into the sump pan/engine, this will give you an indication of how much oil is in the tank while it is running. I think on a K series it was about 9", not sure if a duratec would be about the same 🤔
Nick