I wouldn't worry about any adverse effects on handling. I've worked in GM dealers since the 70's and have seen a ton of GM cars with the rear bar against the pumpkin. In theory, any bind that would inhibit the free rotation of a torsion bar could cause inconsistencies in its response, but I've never seen one bent that bad. Usually, due to lack of attention in lifting with a jack or hoist, the bar makes light contact at best, nothing that would truly put it in a bind. FWIW, the '78 version of the rear bar runs straight across from side to side, passing across the rear end cover rather than below it. I have one of those on my '87. I like the idea that my bar is a straight piece of material, rather than having bends in it, giving a more consistent response in its absorbing and release of energy. But we're really splitting hairs here.
Bill