MSD -vs- Jacobs

Not to stop the bashing, but getting back to the OP.

What makes you think throwing money at your ignition will make your gas mileage better? It sounds like you have a reasonable combo now. What about your carb, cam, converter and gears? Whats your MPG now and what do you want to gain? A couple #s leaner on your main jets and more vacuum advance would be a good start.