Where are you timing tab?

The 71' (or 70'?) and up normally have a cast timing mark in the cover on the drivers side. Read that there is one year that mark was cast in on passenger side but never seen one. If a cast iron water pump with the drivers side inlet was put on the engine and the timing cover not changed to an earlier unit, the mark will be behind the water pump fitting. We just put on the tab from our previous cover (bolts on the passenger side) and remarked (scribe new mark or timing tape) the balancer to ensure TDC alingment.