If your talking about a 62-67 Z bar, then yes. You need to gusset the sides to give it strength. The picture is from a member here and this was his take on it with heim joints on the pivot points to lessen the stress on the arm or Z bar.
Good picture. I've seen guys gusset both arms on the Z-bar, the inner and the outer. The heim joints will help, as will keeping it lubed. The factory system for doing that uses '20's technology: a grease zerk, some cups and a felt washer, so keeping it lubed, in my experience, requires removing it and greasing up all the joints well. As guys drop in powerful engines and, with them, beefier clutches, the effort required to disengage the clutch is way more than the factory Z-bar was rated to take.