Abstract: The present disclosure provides an oil pan for an internal combustion engine with an integrally formed tube assembly for transporting high pressure oil from an oil pump to an oil filter and back. The oil pan uses a welded tube assembly including two tubes which are placed inside the oil pan during permanent mold casting. The two tubes are individually bent, then welded together, and finally leak tested. As part of the casting process, an end of the tube assembly for the oil pump is printed to a cope of the tool. Another end of the tube assembly for the oil filter includes a threaded fitting screwed into the tube assembly. The fitting prints into the cope of the tool.