I don't recall ever seeing a hollow sway bar. It's basically a torsion bar made to twist to some extent and transfer some force from one side to the other. My experiences with twisting pipes in a torsional fashion never ended well in the long run. :realcrazy:
They make hollow sway bars for A bodies. You can buy them right off the shelf. They’re chrome moly and thick but weigh less than traditional solid sway.
that said, I don’t think it’d try to run a hollow bar on the street