You're right, there is no nut, they screw into the mounting point on the LCA's.
And damn, I just threw away the bags for the mounting hardware last week. Maybe I have them or the receipt somewhere, but I'm pretty sure I chucked em.
About the D bushings and brackets, the ITR bar is pretty stiff, you might want to look into a brace of somekind for the subframe, as some have had issues tearing them out.