Timing mark on 85 E350?

[dansvan]

How can I use a pulse timing adapter and dial back timing light to set the timing on my 1985 E350 with a 6.9? Is the mark on the dampner TDC for cyl#4? And I can dial it back to zero with the light to see where I'm at? Snapon digital timing light. 360 Degree capable. Thanks guys. Dan

 

[dansvan]

If I have this right I can dial out the 20 degrees of offset for the magnetic pickup, then adjust for the difference between lumin probe and pulse, and set from there. Am I on the right track?