Which Carb Gives a Balance of Power & MPG?

If you want the best combination of power and economy EFI hands down.

Unless you drive a lot of miles you won't beable to justify the cost based on fuel savings though. I would stick with either of the carbs you have and get them dialed in even if it means taking it to someone that is experienced. And if you do, if they don't use a wide band O2 sensor & dyno to verify then find some one else.

The Road Demon Jr is just a cheaper version of the Road Demon, it has less adjustability than the Road Demon.