I've got a spare and it sits on a 2x12 board where the bottom studs are recessed into the board and it will sit flat on the bottom. What have you guys done to use a bag as a jack? What did you put on top to keep the stud and air inlet from being the high point? What inflation device did you use to allow to add and remove air from the bag?
The studs will be on either side of the axles. 90 deg 1/4' street ell and extension hose with needle valve on end and air fitting . Plug into your aux air connection next to LP tank. Stick to slide to position and can use hose for recovery