This may really be out in left field, but is there anyway you could turn the leaf over? Run them upside down?
How about the old Mopar way of moving the springs in when you add bigger tires. They would weld in new spring mounts on the inside of the frame rails. You could do that and set them as high as you could or till they hit the bed.
You might get away with what you have if you have a set ladder bars added. I'm with the rest of the guys on this one, if the tires ever hookup, out comes the driveline.
