pinion bearing preload question

Thanks for all the input. I usually did mine by feel too but this is for a customer so I am buying a KD 0-60 in/lbs torque wrench. It is only $40 if you shop around. The rear is a 12 bolt and I am installing 4.10's and a new eaton posi in it. It is going in my friend Tom's '66 Biscayne with a big block and a four speed so I want to make sure it is up to the task.