If you look under the X along the frame at the rubber mounts that go between the body and the frame you will see the bolts going through the mounts.
there will be ten bolts and mounts in all.
the rear ones are the worse hit by rust, due to there location.
Anyone that does the body lift would ask you to spray them down so they may break free easier.
The same is for the rear shackle bolts
and also the torsion bar adjusting bolts that are located on the crossmember under the transmission.
there is a long thick nut and another shorter nut on top facing up.
the adjuster bolt head will be facing down. spray the bolt, the nuts and where they go through the adjuster arm.
Just spray down everything and keep repeating it time to time, so it will penetrate into the bolts and nuts.