Anyone tried one of these HEI Distributors?

Ran the first tank of gas through the Dart after the distributor/coil upgrade.

My 4 tank average before the upgrade was 11.4.

My first tank after the upgrades was 13.3.

Besides the new distributor and coil, I also increased the base timing from 10 degrees to 15 degrees advance. Not sure if timing alone could account for 2 mpg. Spark plug gap remained at .035 for most of this tank.

Just before filling up, I regapped the plugs from .035" to .050". I will post again on the next fillup.