It’s been a while…273 build.

The water pump discharge will obscure that cast timing tab
Without power steering you can JUST see the marks on the driver's side with the cast iron water pump.

I have a stock 67 273 with a 70 up cover so I have both marks, AND on a side note the two are not 90 deg apart. So if the marks on the damper are designed for a pre 70 SB they will be off with the 70 up cover and visa versa.