If it's a stock/stock cam 440, any efi system will have no problem. Tuning issues only start getting more difficult with high duration, large overlap cams.

While I have an efi system for my car, for a cross country trip, you're not going to see a whole lot of gains out of it. The best gains with the EFI is cold start/warm-up and city driving. For real gains you should be looking at port EFI systems, not throttle body. Steady speed driving, with engine up to temp on the open road, I wouldn't expect to see any measurable MPG improvement over a well tuned carb for this application.