For +8s, the axle is a 7HA
Salisbury quote 95-105 ft-lbs for the early style 7HA axles (I.e without crush sleeve).
For the later style 7HA axle, the crush sleeve was designed as a single use with the torque on the nut setting the pinion preload. Torque setting ??
The work round is to mark the nut & the pinion with centre pops or a line and count the number of turns and flats when removing the nut - for reassembly - wind the pinion nut back on with the same number of turns and flats. As you're unlikely to be able to count this when using an impact gun it's use will not be ideal.
