I've used them in competition applications, but never on a street car. Their description is what they are/do. They aren't magic dust that cures all sorts of handling woes, but they are an additional step you can apply. For a street car they may not allow as much travel in both directions as a shackle. It also is very important that you mount them in line with how the leaves slide so you don't create a bind. On an E body that means you would need to mount them with a 1.5 degree angle off center so they are inline with the spring pack and not the frame.
