I don't know if this will help, but take a look at a stock torque tube truck. You will notice that the rear wheel is not centered in the wheel well. At stock height, it sits foward a couple inches. I believe it this is because of the torque tube hinge set up, under load the axle would move back with the springs. If you want to center the axle, you do need to set the mounting hole farther forward.
Steve O
