The customer has bought a rebuilt engine to install but I want to make sure that it doesn't happen to this one.
It looks like what happened on the other engine is that the torque from the starter elongated the holes in the starter mounting bolts (they were OEM with the knurled potion towards the threads). Once the holes were larger it caused the starter to torque more which in turn cause the threads on the block to get ruined and the bolts worked themselves loose.

So, again, we have installed the bracket kit and the time delay
kit so what can we do to prevent a recurrence of the problem on the new engine?