If you already have a chip, send it to them and have them do a ballpark tune on it to get you there. I think you will be adding way too much fuel for that long a drive. You'd be stopping at a gas station every 30 miles. Not to mention the driveablility issues and the potential for overfuelling damage to the cylinder walls.
If you are just installing another Eaton, the injector swap isn't that difficult and I would recommend doing it when you get to Chicago. Should only take about 30 minutes or so.
If you are going with a KB or something else, then that is a different stroy.
Dan