yes the gear on the 777 changes its tilt so as it can fit into the wheel well, the question as I read it is, as most a/c with multi bogeys the gear tilts with the rear axle down, why does the 767 when gear extended for landing does it tilt with front axle down? The 346 centre gear tilts front axle down where as the main gears don't and it has nothing to do with so it can fit in the gear bay. Gear tilts change so that they can fit in the bays yes, but that doesn't explain why the normal config of the 767 is tilted front axle down.
Unless it is simply to fit in the gear bay!