In reply to Porsche's scenerio... if everything was equal and truck #2 had the revolver fully open then truck #1 would have had it's unweighted tire 1.5 inches off the trail. If this was not the situation then all the other variables were NOT equal.
There is some merit to the fact that a mostly unweighted wheel still contacting the trail (revolver) really isn't doing a lot more than a tire floating an inch off the trail (standard shackle) but I would argue that some pressure on the stuffed tire is transfered to the other tire and does help the LSD work more effectively.
I do not believe that revolvers magicly change the laws of physics or drasticly change weight distribution. If your revolver is opened up then a standard shackle would be floating the tire... either way you should be sure what your line holds for you because your balance may be nearing the limits.