Originally Posted by
service1010
...How can I tell which version of (sigh) the Boeing 737-800 goes from IAH to PTY? I have looked at every version on Seat Guru until my eyes are crossed
It varies. The 737-800 version you are booked on now may be swapped out for another configuration at some point.
Go to your reservation and choose select seat. You'll see a seating diagram of the plane currently scheduled and you can compare to Seat Guru for the version. Best way I find is to note on the UA seating diagram the row numbering in front of exit row 20 and the number of the last row.