I claim the ornamental design for a 13/16-inch-spark-plug-socket hot rod wrench, as shown and described.
FIG. 1 of the drawings is a perspective view showing the front, right side, and top of a 13/16-inch-spark-plug-socket hot rod wrench embodying the design of my invention;
FIG. 2 is another perspective view showing the back, bottom, and left side of the hot rod wrench;