I was going to change the rear shocks on my cutlass 69. The left side worked well, except one screw was not tightening up all the way, and the right side I could not get the nut from the screw, since I can't get a grip to the head above the plate where the shock is mounted on. So my question is, what tool do you use to hold that screw while you take the nut up or down?

 

There should be room to put a six-point box end wrench (spanner) on the upper head of the bolt...if the bolt is very long, then use a vise-grip pliers on the very end of the bolt and turn the nut...then as the nut moves down the threads use a needle nose vise-grip on the exposed threads above the nut...also heat the nut up to red hot to loosen the rust, and if all else fails then THE TORCH...