I went out this morning and took a good look at the situation. It is the correct location for a 1/4 NPT fitting (above the oil filter). It still looks like a freeze plug was put in backwards. I tapped at it with a hammer and pointed chisel, all it did was make marks. If it is a freeze plug it should have at least dented. I got this engine still in the crate. Is it a possibility that the rebuilder put a steel freeze plug in the oil sender hole?