Clamping front of leafs as good as traction bars??

I am setting my Dart up as a vintage street car from the early 70's. As I remember many people ran traction bars. I have read here that clamping the front of the leaf spring is actually better than running the bars. I was going to clamp the springs and run the bars for show only. Any thoughts on this??

http://www.summitracing.com/parts/SUM-770500/?rtype=10