The Performace suggests that at 185,000 tons
Must be one of the heavyweight 737s!
In reply to a previous post, full flap on the B757 is Flap 30. F20 is used for single-engined landing and for 2-E go-around.
It's a while ago, but I seem to remember a limit on how much flap is permitted (or recommended) with speedbrake - was (is?) it less than F20?