Classic or NG?
FCTM under "Cruise Speed Determination":
ECON cruise is a variable speed schedule that is a function of gross weight, cruise altitude, cost index, and headwind component...
..Headwinds increase the ECON CRZ speed. Tailwinds decrease ECON CRZ speed, but not below the zero wind maximum range cruise airspeed.
In the same section you also find the that for NG, wind correction is
not applied for LRC:
LRC is a variable speed schedule providing fuel mileage 1% less than the maximum available. The FMC does not apply wind corrections to LRC.
(Strangely it
does apply wind corrections to LRC in the classic, thereby not being a "true" LRC according to the definitions).
Hence, in the Classic LRC may be the better option.
Edit, disregard - see my next post.
CI 0 gives minimum fuel used.
No, that would be best holding speed from the holdings page, which is more or less equal to max endurance.