Perhaps using Redline 80W140 or Redline Shockproof 75W250?

This diff is already bad, Im just looking to buy some time and alleviate some noise.. Will this help or hinder?

Ive only heard of one person trying this, but never heard back regarding any results. Any comments?

Im actually trying to mask the noise a bit. I have faith the diff will last for a while and plan to replace before summers end, just looking to quiet it before it makes me nuts. Will the heavier oil excelerate the problem.

on exactly what is wrong with the diff. The noise you hear is the ring & pinion being miss-aligned from a bad bearing, or bad ring & pinion. The ring & pinion making noise will also cause excessive heat and slivers of metal to accumulate.
Since the diff is a sealed unit these slivers of metal cause all sorts of damage to surrounding parts! Usually the bearings are what suffer the most. A heavier oil may or may not help, depending on the level of current wear which already exists.