I was able to get somewhere just shy of -2 degrees on my mocked up BJ front end. A lot is dependant on how well centered the beam adjuster is. There's enough slop in the (avis) adjuster grub screw fit that it's easy to bias a degree or so towards one side or the other.
Rather than bend the arms, you can flip the upper torsion bars over and re-drill the outer grub screw locations a little further inboard. You're only talking about a degree or two, which means careful measuring before drilling. I think if you need more than that you may need to do more to limit body roll.
Jeff