Panhard Bars.......
Evilmess,
My experiences with panhard bars are pretty all encompassing since I race stock cars (open wheel modifieds on dirt tracks). Let me say first that I haven't seen article in Hot Rod magazine to have an opinion on it except to say that if they are doing it then there must be something to it.
In circle track racing the panhard bar is used firstly to locate the rear end housing laterally within the chassis left to right, and of course on your cougars the leaf springs do that for you. Our second application of the panhard is in the way we mount it and the length of it as well as the heighth of it in the car is all used to manipulate the way weight is transferred in the car from the inside tires to the outside tires in a turn....which in our case is always to the left so the weight is transferring to the right side.
An example of it's use is that on a tacky track with lots of traction built in you might want to raise the panhard mounting locations on both ends to free up the car and lessen body roll. Without going into too much detail you have what is called a moment arm that exists between the center of gravity height in the car and the roll axis. The lesser the length of this "moment arm" the less body roll and in turn less weight transfer.
Later in our race nights the dirt track becomes what they call dry slick, almost like asphalt racing. In this instance it is beneficial to not only lower mounting locations of panhard but to actually put some angle in it to encourage more downforce on right rear tire during cornering. There are times when doing this that not only do you encourage body roll and traction, but you might get it so tight that with our 750 horsepower engines we might have the left front off the ground so high you can't see the guy you are trying to pass! So panhard bars do affect handling dramatically if done right.
Other systems to locate rear end in car exist besides panhards and leaf springs......a good example is a jacob's ladder, which is designed to eliminate bump steer in the rear during cornering, but that is another topic......hope this helps........Keith