If you jack the frame up (or take the rear wheels off) and let the springs extend down that effectively shortens the torque (or at least moves it farther to the rear.) It's basic trigonometry. In a triangle with the hypotenuse (the torque tube) held constant length, and you lengthen one of the sides (the distance from the frame to the axle), then the other side HAS to shorten (move the end of the torque tube to the rear.)
