If I recall correctly the timing mark for the #1 and #4 cylinders is a little wider than the other two marks. You can use the second mark to check the timing on the #2 and #5 cylinders, and similarly the third mark for the #3 and #6 cylinders.
If your car is running at all, then the mark you see with the timing light hooked up to the #1 spark plug wire almost has to be the correct mark. Same for #3 and #5 wires and the other marks.
If the car isn't running then you'll have to pull the spark plug on the #1 cylinder and turn the crank to get the cylinder to top dead center, and see which timing mark is at about the 11 o'clock position on the torsional damper if you are looking at the damper from the passenger side of the car.
Hope this helps. 
