Slant Six distributor question

I generally tighten the top bolt (the one on the dizzy) in the middles of its slot. That way if you find yourself needing a little extra adjustment one way or another you can get it without pulling the distrubutor. You use the lower bolt for actually setting timing. If you need more adjustment than the two slots allow then it is time to pull the dist and move 1 gear tooth in the direction you need.