You need to start at the beginning on your tune. Since you have an auto, you want the most vacuum that you can achieve at your in gear idle rpms. With the brake applied (emergency brake or someone pushing on the brake), adjust your metering screws to obtain the best vacuum reading. Do no worry about the vacuum reading in N, you want the best vacuum reading in gear with the brake applied. You may need to work with your initial timing to get this vacuum reading up.
Once you have your in gear idle vacuum reading at it highest, look at the A/F reading. This might be as rich as the 13's. After you get this set, then take it for a drive and watch the A/F readings at light throttle and cruising up to around 55-60 or so. Write down the A/F readings at the following:
In gear idle (with brake) A/F=
30mph A/F=
40mph A/F=
50mph A/F=
60mph A/F=
70mph (if you drive at this speed) A/F=
(If you are anything leaner than 15, then take it easy on the throttle so you don't hurt it!)

Once you take note of the A/F readings at these speeds, then you will be able to watch what happens at these same speeds when you make a tuning change in the future. Taking notes is the best way to keep track of your changes.