Don't know what fiver you have, but many have 'flipped' the axles to where they are under the springs instead of on top. Same result as blocks...
There is always the option to put a spacer tubing between the shackle mounts and the frame--simple, but needs competent welding.
2016 Tiffin 40 QBH
2015 38RSSA, traded
2005 TK3 #1869, 10 yrs of memories,
2017 F450 KR--one more Ford is it
2009 F450 4x4-died; 2010 F450-retired