Years ago I bought a GMPP package that included the tubular trailing arms, I had serious trouble getting the old ones off so I didn’t do it. Recently I replaced the rear sway and decided to install these arms. It was a PITA to get the old ones off. I realize the factory ones are stamped steel and the new ones are tubular. I am wondering what the purpose of the trailing arm is and what is the improvement of the new tubular ones?