If you restore your backup, it's going to take everything back to the way it was before the upload. Your fuel calibration shouldn't have been nuked, however, during the upgrade. If you send zipped backups of before and after the upgrade to support@dynonavionics.com (reference this thread), we can take a look and see if there's a way to preserve the calibration, and learn why yours didn't persist. There's a chance you may need to redo that cal in the end, though.