Crab distributor initial setup

[Pandersen33]

Im trying to install an electronic crab distributor -speedway 910-8353 in my 39 motor. The engine starts and runs but id like to get some more info on adjustments. Is this thing adjusted by loosening the 3 mounting bolts? Where are they normally set? My motor has no timing marks so without tearing it apart id like to how this thing is set up. Their tech support was very little help. Directions require a timing light which would require marks...