I looked in your gallery and saw that pic. You look to have the 78-87 XJ6 suspension.
http://www.welshent.com/catalogs/welsh_xj6.pdf
The top ball joint has shims that can be rearranged to move it fore and aft for some minimal adjustment. I would see about plug welding the mount holes for the upper arm and redrilling them or if your lower is an easier move look into that. I would shoot for 4-6 deg of caster. More caster will give better self straightening but heavier steering at lower speeds. Nice results on the minimal bump.