New Equal-I-Zer Hitch Issue

I took my hitch to a heavy truck maintenance shop. They have the torque wrench that will go high enough and they have large thin walled sokets. If they charge it is minimal.

I put my hitch head upside down into the truck receiver. Note that there is a flat area on the ball side for a wrench to hold it steady while tightening. (it takes a big wrench)