Only problem is if you ever want to move your box forward to accomodate moving the axle forward, the line coming off the box will interfere with the front body mount. I prefer the second location. Roughly 2.5" down from the top surface and 1.25" over from the casting seam. It is out of the way and allows for you to move the axle in the future without redrilling your box.
I would locate this hole closer to the steering shaft if possible if I were doing it again. I would have to look at it to see if it is possible. I ended up lossening the fitting with my tire.
39 iroks on 2" bs rims
steering box all the way forward
front axle 3 1/2"-4" forward
Note this was not a problem when the axle was 2" forward. Now it only happens at full stuff, wheels turned passenger.