The announcement of YYC-LIR (Liberia, Costa Rica) got me thinking of the 10 longest 737 routes WS flies, so I
plotted them. The time is mach .79 in still air, and I dragged Hawaii closer to YVR to shrink the map.
I kinda went off the top of my head so may have missed something - YEG-CUN, YHZ-GLA, YYZ-POS are all shorter but let me know if one is longer and I'll plot it.