Have you seen the Andersen levelers? You can get either one or two, depending on how many axles your camper has. We are very happy with them - and more variable and lighter than solid lumber.
Andersen levelersRob
U.S. Army retired
2020 Solitude 310GK-R
MORryde IS, disc brakes, solar, DP windows
(Previously in a Reflection 337RLS)
2012 F350 CC DRW Lariat 6.7
Full-time since 8/2015