Ditto on lifting the body with a couple of 6X6's- - - - -4X4's might work, but the bigger timbers add a bit of rigidity and safety factor. Investing in a couple of "high lift" jacks (bumper jacks on steroids) would be a good idea. They can lift approximately 3 feet without repositioning anything, although you don't need to move that much in a single lift. Use one on each end of the 8 foot long timber, and a helper to operate the other jack- - - -lift the rear about 6", move to the front- - - -lift until level- - - -repeat as needed. Use tall jack stands to support the timbers between lifts.
Jerry
