Ok, I was wondering since others said this was not common, and in my experience it has been VERY common, so I just went and measured all 5 of our vehicles.
My d-max and dw's z71 tahoe- drivers side is 3/4" lower than pass. side. (This is at the rear, with fronts even. )
On 2 of my cars the drivers side is 1/4"- 1/2" lower.
The third car, dw's Impala, the pass side is 3/4" LOWER than the drivers side.
As I said in my last post, 1" +,- is no big deal, you will probably find variations on every vehicle.
MillerTime- Future Sabre Handler!!