Jeep was claiming for a while that you could slap 37's on the JT without a speedo recal. I dont know if they have changed or redacted that or if it was a bit of an FCA overstatement. Or maybe youre just lucky.
Another thing I should've mentioned. I had my wife drive next to me(in her JLU) on the highway to compare speeds real time, I was doing 70MPH, on her speedometer said 79-80 mph lmao, I should prolly believe the real time test lol. I'm still gonna get a tazer mini regardless.