Starting at anything other than 12 o'clock just adds a second set of useless numbers. Just base everything off of 0 at 12 o'clock. Notice that:
1. If the dial indicator needle moves inward (shorter) it produces a positive reading.
2. If the dial indicator needle moves outward (gets longer), it provides a negative reading.
Something seems off about your numbers because you should't have negative numbers opposing each other at 3 and 9...the fact that you do suggests you don't have it set up right. You can't a -.011 reading at 3 o'clock (meaning the hole is off to the right) and at the same time and the have it be off to the left at 9 o'clock give you a -.012 reading.
My advice is to loosen everything and make sure both adjusters are positioned so that the thickest part of their bodies are at 12 o'clock. Take new readings, watching the needle as you go, and repost here.
This was very helpful for me:
Lakewood Bellhousing
Another thread with pics:
How to dial in a bellhousing/scattershield - Lot of pics - Chevy Nova Forum