Questions about 318 timing

Hi guys,

I finally got a timing light and decided to check the timing on my 74 dart sport. It has been running and driving fine, but the gas mileage is really poor.

If I did it correctly it looks like I have 21 degrees initial and 15 degrees mechanical, is this correct? What, if anything, should I change? I checked the initial at idle and the total at 2500 rpms.

-Russell