Can someone educate me about lower control arm brackets on the rear suspension. I was told they were part of the F41 package, my '68 has a aftermarket rear sway-bar but no brackets. My question not is, are they worth installing and where are they mounted?

brackets were on 4 speed cars or el caminos. Attach between both rear front most lower and upper control bolts.

My '72 Malibu had these brackets. It was all original when I bought it, was it something they decided to put on all cars after a certain year?