[Oldgearz]

I plan on putting in a Mitchell Overdrive unit in my 30 Coupe. I'm on a waiting list to get the unit, so in the meantime I'm stocking up on tools to do the job by myself. Just got a pinion gear puller and installer from Synder's, and when I looked at the instructions I was surprised to see that the puller was also manufactured by Michell Manufacturing. Instructions for the use of the puller said to remove the two large pinion bearing nuts after carefully dimple punching the inner nut to mark its location relative to the keyed slot. Then take off the nuts to install a backing plate. This would destroy the preload for the bearing. Other instructions I have seen regarding the driveline say to remove the pion gear and bearing nuts as a unit so as NOT to destroy the preload. Question is, can the preload be accurately reset by the punched dot method or is it better to remove the unit as an assembly without affecting the preload. Since preload can also be reset using a torque wrench, is it really that sensitive? What's best, keep original preload, use the punch point technique, or use a torque wrench. I'm just a shade tree.