I use 12T jack standsthough I didn't measure them for height. I found that if you don't disconnect the lateral rod, you still have to have someone stand on the hub to push the axle down just a bit to get the spings out.
That's what I was thinking too. They range from 24-30 inches at max height depending on brand. I couldn't find any 3, 4, 5 or 6 ton that went that high.