New Nivomat Shocks but ride not level

[FloridaTahoe]

I just had new rear nivomat self leveling shocks (OEM ACDelco) installed on my 2004 Chevy Tahoe LT. It has 157,000 miles so I figured it was time to put new ones on. After much research I determined the nivomats were the ones needed since it has the premium smooth ride suspension. The ride tightened up a bit and raised the back end an inch or so but one thing I noticed is that the back is not level. At close glance you don't notice it but I happened to observe this when my wife was driving the tahoe and I was following in our other car. The more I looked, the more it seemed like the right rear was a little lower than the left rear. So, when we got home I pulled out the measuring tape and indeed the right rear is riding about an inch lower than the left. I had a local garage put the rear shocks on. Is there anything anyone can think of that would cause the unlevel ride? Or is there very specific, out of the ordinary installation steps that are needed for these shocks that the garage didn't take? It seems like these would be a standard installation for rear shocks. I know it's just an inch being unlevel but I spent $500 on new shocks and also just put new tires on. The tahoe is our family vehicle and I plan on keeping it around for awhile and the fact that it is not level is driving me crazy. If anyone can offer some insight it would be greatly appreciated.

 

[DPGDirk]

Same problem here...

 

[BADRIDES]

My 02 model has the Nivomat shocks with 194,000 miles and mine sits about a half inch lower on the right side.

 

[Searay45db]

Coils. They went out long before the shocks do. I actually put the air bags in the coils, didn't do the compressor, just keep them around 15 psi, it gives the coils a break and it is even steven. 185k. Zippo problems and not that hard to install.

 

[BADRIDES]

I'm putting air shocks on mine tomorrow