I don't think I've ever seen a published figure so would go with Andyd approach.
Andy is correct when he says there is a flat washer behind the castle nut but for work holding purposes probably easier to file the back of the nut.
Before you bolt the hubs up, check and double check the keys are located correctly in the slots on the shaft. Get this wrong and at best you will distort the surface that the oil seal runs on leading to a leaky rear hub and no rear brake, at worst you will crack the rear hub.
Arwyn
