[rgunlock]

Just to wrap this up, I did get a decent impact wrench - not sure how I've lived without one! - but the stud continued to spin when I used it. I did mount the axle onto the truck and after removing the lower grease zerk I jacked up against the bottom of the knuckle until the weight of the truck was on that joint but the stud still spun.

I was finally able to get it to tighten by using a small pair of needle nose vice grips at the top of the grease boot just under the "C" and I don't believe that it did any damage.

Thanks for the suggestions.