I have mine rock solid.
It is a 40 footer, and I have it on a permanent site. We will be snow birding in it for six months.
Don't jack it up. Just get it perfectly level and then put down your stabilizers. Then use concrete blocks for piers.
On some of mine I needed two blocks and on others places three. On top of the blocks I used shims, (cedar shingles)pounded in.
On some of them I also had to use treated lumber, (2" x 6"'s) between the top of the blocks and under the shims.
I used three piers on each side.
It comes out as solid as your house.
Jack L
