Curt,
I noticed you are running a 12-Bolt rear end. Has the 12-Bolt been modified or did you just bolted the rear end from another car?
The upper mounts on a GM 12-Bolt have a different location to the rear ends used in G-Bodies.
There are kits available for the 12-Bolt swap on G-Bodies from various companies such as UMI Performance and others.
http://umiperformance.com/catalog/in...products_id=76
http://www.maliburacing.com/iceman/G...%20uppers.html
http://www.maliburacing.com/tech_rearend_swaps.html
http://www.baselinesuspensions.com/kits/chevy.htm