Did you disconnect the wire to the BAT terminal on the cap when the above results were observed?Ok I had 12.43 at the battery and 12.26 at the wire that goes to battery side of the cap.
If so, your HEI is wired correctly (as long as the gauge of the hot wire is adequately sized).
I am not sure what is supposed to happen when you do this test as the hot wire is still connected to the coil.I took the top of the cap to expose the coil. I checked voltage on the coil side of the connector and it was only reading 2.5 volts at the blue circle in picture.
Also, where are the screws that hold the coil... and the coil's ground strap in place?