You gain nothing with adding the transmission controller computer over the fulliy manual 700R4 transmission. The 700R4 relies upon RPM and line pressure to activate the electrically operated lock-up clutch in the absence of an OBD II computer. If you are thinking of going further and submitting to the dark side by buying into the EFI myth, then it might be justified.
Just want to point out that a carb makes more power, allows a more radical cam than EFI does at one sixth the expense. A carb won't win a mileage contest, but few buy high horse V8 motors to get better mileage. The reason the factory went to EFI was to pass emission tests.