City Fuel Mileage?

My Dart has the original 318 in it and when I was running the stock BBD 2 bbl it got 12.7 in town with a 904, duals, and 2.76 gears.
Now it has a performer intake, Thermoquad, 340 exhaust, 727, 8 3/4 with powerlock 3.23 gears. It gets around 11 or slightly better or worse now in town.
I got 15.5 in town with a stock /6 69 we had for a while as long as it wasn't loaded with 300 pounds of parts in the trunk so getting 15 with your car is excellent.
Don't touch anything and be very happy.