Dealership test for Taco Lean

Does anyone know how the dealers test/measure for this? My truck has about 3/4" with a full tank. Also, anyone know what "acceptable range" is within factory specs? At 7k miles I am not happy about it, but if I can go into the dealer with measurements done on my own using their method that would be helpful.

 

The testing procedure they used on mine was to measure new trucks on the lot and say mine was better than them . They had other interesting methods for other complaints I had so I do / will not go back to them again .

 

I hope mine doeesn't do that. Luckily mine has been pretty good so far and all the issues I brought up were legitimate problems