calibration

Hi, I have a 2018 Charger. I just recently bought a 3.07 rear diff to install and dump the 2.62 it came with, Now I have a big problem, I cant find one speedo calibration tuner for this car. Does anyone know of a tuner just for speedo/ tires calibrations. And if nothing else a full tuner that...

Just as an FYI regarding the "clicking" sound you can hear when the actuators are going out. I got the clicking sound mainly after shutoff. It eventually stopped but then I noticed the car climate system was only using cabin air. Not good on long road trips with teenage kids! Not really...