While it was up on the lift again this week, I took some measurements with full droop in the front and it looks like the maximum backspace we can live with is about 5". Any more than that and you risk bending tie rods. AEV has promised to reimburse me for the wheels (yea!) so I'm going to get some steel wheels with a 5" backspace that I won't have to worry about nicking up on the rocks.