Noisy rearend 69 barracuda 318 car

Don’t want to hijack your thread but have a question for you guys that know rear end issues.

I’ve got an 8-3/4 center chunk with 2:76 gears that I was considering bolting in just cause I may be doing a long road trip. Anyway I’ve run this chunk before on a different car and I know it has a whine , only when decelerating. Any idea what the issue may be in that case?
Probably nothing to worry about.
The pattern is just off a smidge, and after it has a few thousand miles on it , it's doubtful it can be changed. It will likely whine forever