There is not a TORQUE rating on the nut- There is a spring turn load torque on the preload of the bearing. 15-20 inch lbs. this number will very from bearing size and rear end size.
IF you are NOT replacing the crush sleeve and just trying your luck on a reassembly tighten the nut till the bearings seat then creep up on the drag...used bearings will have a different perload spinning torque rate 10 ish
This ALL usually is done WITH OUT THE carrier (posi or open in the housing.
So what do you do? snug up the 1 1/4" pinion nut tighten it with a 1/2" ratchet as tight as you can stock length ratchet nut having lock tight and then --- using a punch stake the nut to the thread of the pinion where the nuts tapered edge meets the thread...REMEMBER STAKE THE NUT not the thread of the pinion. That will keep the nut from backing off under high quick load conditions. (IE burn outs!!!)
This is done on every rear we build. Safety precaution. We have seen NEW nuts fail and lock tight fail ...BUT not yet has this failed us. IT WORKS
I wish you the best on the reinstall if you have not done it already.
JIm