Looking at the photo, my guess is that "flipped axle" is being used to describe the front axle beam being mounted above the springs (with spacers to make it even higher) instead of below to raise the spindles relative to the frame and the rest of the truck (or lower the truck relative to the spindles and ground, just a matter of persective).
It would change the steering geometry but I don't understand well enough to say if better or worse and how much. But you would hope the original designer put in the effort to be fairly close to "best practical". One thing I am sure of is that if a new hole is drilled as mentioned in the pitman arm, closer to the steering box, the angular travel limit on the pitman arm will be same but the shorter effective arm will have 2 effects. One is that the steering efort should go down roughly in proportion to the shorter effective arm. The second effect is that the wheel cut angles will decrease and the turning circle will increase. A shorter pitman arm will make less linear travel in the drag link for the same angular travel which in turn will reduce the travel at the steering arm on the spindle. I would also want to be sure there was enough material left on the pitman arm for strength. Most stock pitman arms are enlarged around the drag link attachment point to keep the full section once the hole is taken out.
