340 has no timing tab...

This all makes sense...

73 car would have AL water pump, the inlet on pass side and timing mark on driver's side. Radiator would match

67 and 68 have bolt on timing marks on pass side, cast iron water pump, and the inlet would be on the driver's side. The radiator would match.

69 was a unique year. The timing marks were cast into the cover on the pass side, cast iron water pump, and the inlet would be on the driver's side. The radiator would match.

Your 73 car has a 69 engine in it.


You few choices.

1. Live with it
2. Change the front cover to a 70 and up cover. Find true TDC And make a new mark on the damper. Or buy a new damper for 70 up with the correct marks in the correct place. Some of the front accessory brackets might need to be changed.
3. switch to a cast iron 69 and older water pump and replace your radiator outlet to the drivers side