When you mock those up, don't forget to mock them up so the bumps are collapsed. Those air gaps will collapse under weight. If you need them taller you could add spacer plates between the bump and mount. Of course that would only get you an extra 1/2" or so before you ran out of threaded stud on the bump.
1975 Ford Bronco stretched and linked
2003 Chevrolet Suburban 2500 4x4