TWA classics - mostly -131s that were purchased new had JT9D-7A mills. These were phased out over time and replaced with mostly all JT9D-7J - more juice and higher EGT limits - 985C on takeoff. TWA also operated classics (bought from other carriers, I believe) with -F engines.
Will check and see what I can find on the United and AA numbers listed. Who's -2U3B ?
