Scamp welds the axles on. When Scamp does a lift they usually weld a 1.5" x "3 piece of frame tube between the axle and the frame. If you want to do a bolt on lift job Dexter sells the bolt on axle brackets and bolts for about $50 a set. Lil-House Customs and E bay sell bolt on lift spacers I think for about $100.
If you decide to replace the axle when you do the lift you can order a Dexter high lift axle which will add 2" above the std. Scamp axle. (Not very expensive for that option.) Since you have a 2011 you can order a bare axle and reuse your brakes
and bearings and save a lot. Don't forget the cost of welding and brake rewire at the axle.