For $5k it had better come with it. You can build a torsion bar suspension that will handle just as well for thousands less.
There are plenty of options, you just have to do your homework before you start ordering parts. And in this case QA1 themselves aren’t being particularly helpful, because there are options other than their sway bar with their K-member. Even considering the mismatch of the 67-72 k frame with the 73+ sway bar tab locations. It may take some measureming and some fiddling, but it’s by no means insurmountable.