I was wondering the same thing. The September issue of Super Chevy has a pretty goog article on it. I called Hot Rods to Hell for a price, it is about 2000 dollars delievered to your door. Basically this rear suspension is the same thing that they used in circle track for many years. The manufacture says that it makes your car or truck handle like it is on rails and also drops your et time at the strip. By having to long control arms you are eliminating the coil bind and wheel hop normally associated with coil over or leaf spring cars with alot of horse power. Also with the long control arms you are making the suspension pivit from half ways under the car. With the Hot Rods kit it uses to coil springs and screwjacks to give you up to 6 inches adjustment in ride height.
I have also found the truckarms and crossmember for sale through www.stockcarproducts.com.