Wow that is high torque, maybe that is the reason mine moves when taking the load bars off the hitch. With the load bars attached the hitch head moves up (pivots on the lower bolt) and the top bolt slides forward. When I remove the hitch bars the hitch head drops again.
I only tightened those bolts with an 18" long wrench, clearly I didn't realize that torque mattered on those two bolts. They are certainly tight enough that the nuts will never back off, so I'm not worried about that happening. I wonder if the torque spec is only so high to allow the proper angle to be set on that top slotted hole and not move like mine does. I will get it set properly now.
I didn't know the torque spec on my ball, so I used two 24" pipe wrenches to get it tight, then I used two 3 foot long pipes over the handles of the wrenches, so I'm not worried about the ball.