Also as someone mentioned, ull have to clear at LAX. If your coming on the 2nd flight of the day that gets here around 630pm (2x daily now), ull have to walk to TB to clear. They close immigration in T4 later in the day. I just came off that flight on fri night, when i got there, there must have been at least two, if not three flights that came in from TB. It was a madhouse. If I wasnt towards the front of the plane, I think I would have missed my connection. So, if it was me, I'd get as close to the front as I could.