From the factory they come with the axle over the springs, and it is a practice to shift the axle under the springs to give you more lift. I had the axles moved to give me about 4.5" of clearance and they did not install bump stops.
This picture, taken under my trailer show the springs over the axle. Not sure where the bump stop would be needed. If the top of the spring bracket hit the trailer frame there is a big problem....