['72 Shorty]

had to use the blue tip wrench on mine. Have new bolts ready, since you more than likely won't get the old ones out. Even if you do, the one that actually unscrewed was so badly rusted that i wouldn't trust it.

My procedure(since I highly reccommend not climbing under a truck with only jacks under it) is to jack the rear up and put jackstands under the frame as high as you can get it. use the floor jack to reduce the pressure on the springs and unbolt them. then lower the jack and take the old ones out. reverse for reinstall.