Why not just get DSS axles? And a stock rear? With the brace and possibly an AAD rear suspension upgrade to square it all up, I would think you should be plenty fine
I am an Amsoil Dealer and about to run the severe gear in the rear with no additives.You try changing the oil in it? Sometimes that quiets them down. Guys have luck with a Amsoil oil and 1/2 bottle of Mopar Friction modifier.
If you open the pumpkin up you will be able to see what is chewed up. My guess when you do the spider gear will be missing teeth and they will be laying in the bottom of the diff.I’ve changed the diff oil every year to be safe. This time there’s metal in the oil. Not sure if it’s the diff or from the axles splines taking a beating so I’ll be changing both.