Mine is in the same range as Bjorn's with the 2.73...but generally to the low end! That's with a 400/TH400. I just did a shift kit, and haven't put on enough miles to determine if there is any improvement in economy.

Gas mileage is generally poor until the engine reaches full operating temperature, so if you do only infrequent short hops your mileage will suffer, and it drops a couple of mpg if I use the air conditioning.