Increase 31.5" tire to 33" diameter tire

[GMSEVEN]

 I have a 2019 T1XX Silverado 1500 Z71 LT with 18" wheels and 265/65/18 stock goodyears with 31.5" diameter.  I want to increase to a 275/70/18 or maybe a wider 33" or even 34" diameter tire.   The RST's with 20" wheels come standard with a 275/60/20 Tire which is a 33" diameter...

So my question: is increasing from 31.5" to 33" diameter tires merit a rear end gear change or other ECU programming to accommodate the new diameter?   We all know that increasing the tire diameter changes the final gear ratio, but is it significant enough that would require any adjustments?   I would doubt that an LT 8-speed and 3.23 rear gear and RST 8-speed and  3.23 rear gear would have different components internally even though the tire diameters are different by 1.5".

Any comments would be appreciated,, probably nothing to stress about but my perfectionist mind likes to dwell on small details, and don't want to experience any acceleration changes, fuel economy decline or speedometer misreadings.

[CamGTP]

Changing the calibration isn't a 100% must do thing. It would only be off by about 3mph when going 70mph down the freeway.

 

You have the option to see if a dealership can program the calibration for the 33in size tires that would be standard on the different trims trucks.

 

I don't think you'd want to spend $1,900+ to do the tuning changes yourself with HP Tuners because that is the only aftermarket tuner on the market for those trucks.