Got it back last night, rear end is quiet as it can be! Also now have a new serpentine belt, t-stat, and water pump. It idles a lot smoother now when warmed up, I think my suspicions about the 160* t-stat not letting it go into full loop and causing a rough idle were right, runs so much smoother now! Though that old belt could have been a bit loose too, or the bearing on the water pump may have been on the way out. Who knows, it runs better now though!
My pass rear speaker is on the way out now, no fear, just turned on the HPF and the fade a bit towards the front. Much better ha.