Hmmmm, didn't know the older Edge box was fueling only, since I started with an EZ and then upgraded to the Comp.
I'd suggest looking around for a used EZ or Comp to swap out for your older box. Injectors might help also. I went from 16. 0 MPG when bone stock to anywhere from 17. 5 - 19. 2 MPG when I added EZ & DD3s at the same time, so I can't tell you how much MPG was affected by either EZ or injectors alone.
Tom