15.0 mpg to 21.6 mpg!

7milesout said
No expert here. Break that down for me. :D I only know as much as I've figured out. It's probably the stock ignition system.

Initial timing ~11°, plus mechanical ~37°.

I'm not an ignition pro but I know that if you're not running vacuum advance you're giving up a lot.

I think Mopar Action said total with vacuum would be like 50+?