i have a 2017 ram 2500 with 37" tire and a 6" lift ,how can i calibrate truck for this modification?

 

Need to be able to tell the PCM what's changed. Dealership should be able to do it. (or, any decent shop with a good scanner.)

 

I bought a hardly used Superchips tuner on Craigslist for $175, cheaper than a speedo calibrator and much more useful. You can set the tire size with it. Setting tire size to 37 got me close but I think I ended up at 36.25 I have a GPS speedo app on my phone that I calibrated it with. I don't think the dealers scanner has enough range to get you there either.