You're probably best served with a rod end (heim joint) there. You will notice no difference in ride quality, and it will have zero bind. It will also probably be a little cheaper.
Do not use grade 8 bolt there. That's double shear there, and not compression. An 8 will fracture long before a 5 will.
You'll need to make some spacers out of heavy wall tubing to locate the joint and reduce the shear forces. Something like this, at the frame end of the arm.
