I am booked on AA143, flying out of Logan at 16:45 on a Thursday, getting into LAX at 19:50. I believe it lands at Terminal 4. This allows me 2 hours and 20 minutes to get to Terminal B to catch the QF12 to Sydney. Is this enough time to change terminals, check in (if I have not managed to do so earlier in the day), and navigate the inevitable security circus? Can I hope to get my case checked straight through to Sydney from Logan, or should I expect to have to retrieve it and recheck it?