MPG experiment....1976 Dart Lite

13.5 mpg for combined is pretty poor, I would say you have some issues with the timing and/or the carb.

I got 19-20 around town and 21-23 with a \6 with a comp Cam, offy intake, 390 cfm 4bbl, headers dual exhaust, A833OD and 3.55 gears.