[Barnsnake]

Kevin,
He's not talking about the Panhard bar. He's referring to the four-link bars. If the bars are loaded against each other it can raise one side of the car and/or impede the free motion of the suspension.

Once you have your axle where you want it in the wheel wells (fore and aft), make sure the thrust angle is centered toward the front wheels (you can use a laser level on the rear wheels and reference the front brake rotors). Set your pinion angle with the weight on the rear axle. Now adjust each of your four-link bars a bit each way until they turn easily by hand with the weight still on the axle. When you reach a situation in which all four bars will turn easily you know the bars are not "fighting" each other. Re-check your pinion angle. If it's still correct, lock down the adjustments on all four bars (make sure the heim ends are aligned the same on each bar). Twist them all again to make sure you can still swivel each bar easily by hand. Re-check the pinion angle and you're done.
The rear suspension should now be softer and the body as level as it gets.