The PDF from Wilwood says: Bolt-On Steering Arms - high strength forged steel arms are strong and can be run front or rear steer, or inverted if necessary to improve steering characteristics such as bump steer with relocated or custom mounted steering linkages. You are of course absolutely correct though that the Ackerman geometry would be way off if you were to use them in a rear steer application. I actually thought that the arms were a little bend, so that the tie rod hole would end up more outwards (front steer) or inward (rear steer, with the arms flipped around), but now that I look at it again, it seems to be straight. Since the arms wouldn't work in combination with a vintage Mustang suspension anyway, due to their too high position, I didn't give that Ackerman problem much thought. You could make it work with (a) thick spacer(s) between the arm and the spindle and a long bump steer stud to put the tie rod pivot point down and inward, but it would probably be way too flexible (and ugly too).