I just did this today. I used "Slide-out Stabilizers" made to support slide-outs on RV's and travel trailers. They theoretically support 5000 lbs each and I welded a plate on the bottom for better stability. Once they're under the body it's effortless to crank them higher. They'll go up to about 48" but I only had to raise my body to about 31" to roll the chassis out. Best part: they cost only $39 for four.
