You also can't put longer main gear: as they fold inward, they have to attached at points separated by over twice the height. If you move them apart, you have t

You also can't put longer main gear: as they fold inward, they have to attached at points separated by over twice the height. If you move them apart, you have to make the center fuselage as well as the root of the wings much stronger. That's a much bigger change than anything else.