Classic/Antique Car Repair: Pinion Seal, 1966 buick wildcat, pinion shaft

Question
Iam working on a 1966 Buick Wildcat, and I have to change the pinion seal, my question is do I have to torque the pinion nut ???  Or is there something else that has to be done. Thxs, Joe

Answer
The method that I have used over the years is to center punch a mark on the end of the pinion shaft and then on the pinion nut aligning with it. The remove the nut and install the new seal. Then tighten the nut until the marks line up again. That puts the same crush on the spacer as was there before.
Brad