In NW, the only guaranteed LH equipment is 735/710 operated by an A343. There are a smattering of A33G/A33E on some of the other flight but have not been able to notice a consistent pattern.
The 77Gs/Hs tend to be seen on MNL, CEB, SGN and BKK more presumably of the shorter distance to HKG in case the frame is needed to turn around quicker.