I finally got iTunes 11.1 to install successfully on my Mac. The good news is that for the first time with this Mac iTunes will now sync via WiFi with my iPad 3. That would never work before, but it was probably related to the fact that the iPad had originally been synced on another computer that has since died. My iPhone has always used my Mac to sync with iTunes and it always synced well over WiFi. Anyway, as soon as 11.1 installed I opened it and it immediately found both my iPhone and my iPad and went through a backup and sync of the iPad. The iPad is running iOS 7.0 and the iPhone is running iOS 6.1.4.