TTI Header Knocking Against Torsion Bar

I have a '75 Swinger with a 340. I just had TTI headers installed and the driver side header "straddles" the torsion bar. Now I'm getting a knocking sound from the header banging against the torsion bar. Has anyone else experienced this? Was it installed wrong? I'll check with TTI on Monday but thought I'd ask here too. Thanks.