Who makes the kit that ties the lower trailing arm tie in point(frame) up to the I think the the shock perch. I think it's designed to help in twisting of the rear frame. I have seen them here but I can't seem to find them.
The edelbrock ones are easier to install, but I have also installed the hotchkis. Takes a little time, but they are adjustable in length so you can get them perfect to fit right. Its that #%$#^ parking brake cable thats a pain to work around.