Adjusting negative camber

Guys,
My son's '74 Duster has a negative caster problem....the damn thing looks like something off of Disney/Pixar's Cars....and to be honest, I'm not sure how to adjust it, or what's causing it. It was a 6-cylinder car originally, but now has a 318/904 combo.

I'm thinking it's the UCA bushings that are shot, but I haven't crawled under it yet...would those cause that problem? Would it be too much weight from the V-8? We recently replaced the inner and outer TR Ends, and a buddy of mine said to adjust the torsion bars, but I ain't cranking on anything until I get some professional advice (that's why I'm here :thumblef:)....

Any ideas? (I'll post some pics if needed...)
Rob