8-3/4 Pinion Nut Torque???

If it has a 489 case you tighten it to a rotating torque of 6-9 in-lbs for used bearings, for pinion only total preload with ring & pinion 30-35 in-lbs

read this https://www.hotrod.com/articles/ccrp-1006-mopar-83-4-inch-rear-axle-assembly/