[larrys40]

I do lots of rear axle rebuilds ( have done hundreds ) and have only used a shim once that I can recall.
In my opinion you have something wrong which dictates that. I would take another look at your housings, bearing seats, etc make sure all is true and no burrs etc.

I just rebuilt one and put in a 4 speed and was suspiacious of why the gasket thickness was so great on the carrier preload. Ha!! Someone had used a chisel to unseat the carrier bearings and left witness marks and it caused the new bearings not to seat properly. Caused a .050 difference .

I think you have an issue. Find the problem and correct it. You may not have the experience to identify and not trying to be curt about that but it may be factual so I would recruit someone in your area if there is an experienced A mechanic to take a look at it and assist.
Liked engines even thow they aren’t Brain surgery there is still a methodology and procedure about them that the average guy will most likely not cover or catch because they don’t have the necessary tools and knowledge of their nuances .
Larry Shepard
Expert Model A service