I run my edge comp on 1X1, which gets me the best fuel mileage. Anything higher and the mileage goes down, as low as 12mpg on 5X5. I'd say run it on 1X1 and work your way up. Then you will know. Good luck!

 

No one has asked about your "upgraded Torque Converter", but this may be your problem.
As a general rule, you can add an after market valve body to a factory converter, with no side effects, but the other way around can cause problems.
I know several members have done it but most tranny shops, I think, will tell you not to. A tight converter, for example, could be a serious mismatch and robbing power to the ground.
Whose converter did you go with?

FYI - I get 16.5-17 mpg on my 1000 mile calculations. This includes 70% rural, some heavy hauling but no serious towing. Best ever was 18.5 coming back from California at 75 mph...empty.
I daily drive at about 400 hp.
RJ

 

I can agree with less fueling and more timing. I have a TSTpmx3 and smarty. I use the fuel saver with timing set on 4 and tst usually on 1-3 for freeway this is almost 20 on freeway using a gps . this may be due to you using a auto. also have you changed your fuel filter lately.

 

Mine is going the same way at 250000k my injection pump is tired and fuel mileage suffers just waiting time when pump dies