go find a emty parking lot and drive in a figure 8 for a while,,, work that additive in and see if that does anything.

 

We old Vette guys invented that run-in technique, before 3rd and 4th gen Camaros existed.
If the noise you're hearing is while straight line driving though, and not while turning, then it's not from an LSD additive deficiency.
Slide under the back of your car and have a buddy get in the back and bounce up & down while you track down the noise.

 

Got most of this crap figured out, it seems. Weather cleared up enough for me to get under the rear end and check some stuff out. It seems the panhard bar got loose and was moving around. Keep in mind it's an adjustable panhard, so I'm thinking it just loosened up from the vibration or they didn't tighten the nut enough when the car was in the shop. Either way, I have to wait for the weather to get better ONCE AGAIN so can get the can up and fix it. Got myself some Loctite and a big-*** wrench to tighten the nut down. However, I have a question:

When I replaced the original panhard with the new one, the new panhard wouldn't make it to the slot on the driver's side, so I had to extend the end by a couple turns to make it so the bolt would slide in. I'm assuming that wouldn't be the issue, am I correct? Or should I do my best to resize the panhard to OEM specs?

 

panhard bar holds the rearend side to side motion. adjust untill the wheels are centered (equal distance between tire and fender) with a full tank (of fuel) and a few 24packs (7up) in the back.