Z120 timing mark question

I've searched this forum's archives and found references to inspection ports, peep holes etc. as timing mark locations on continental z120 engines, but I have not been able to find anything other than two lines that are cast on the engine timing cover at about 7 o'clock viewed from the front of the engine. There is a notch on the edge of the crankshaft pulley, but I can't tell if it is a timing mark or a dent. This is not the original z120 engine for my 1949 te-20 so I can't go by the tractor serial number for help in finding the timing marks. Is tdc where the notch on the pulley aligns just between the 2 lines on the timing cover? Any help is appreciated.

Thanks Again, Don