On the 74s I have flown, there is a crossed-tape marker on the window post, the horizontal part being the eye level and the vertical showing fore/aft location. I have to say that I use it only as a guide and that my ideal position is usually slightly above and behind the cross.
As
Intruder correctly says, the main point is that your eye-height on the 747 needs to be such that you can just see over and down the top of the glareshield.
JD
