Want to get rims and tires. need expert advice.

[ckrimits]

Hey everyone. I have a 2014 Sierra with stock 17's Currently P255/70R17 tires

and I would like to purchase new rims and tires which are 275/55-20. I used the tire calculator which I had found posted somewhere on this forum.

Tire Size Comparison

Specification  Sidewall  Radius  Diameter  Circumference  Revs/Mile  Difference255/70-17         7.0in  15.5in    31.1in         97.6in        649        0.0%275/55-20         6.0in  16.0in    31.9in        100.2in        632        2.8%

My question is: being that there is a 2.8% difference overall, and minimal in revolutions in a mile. will I have any issues with my shifting? or my speedometer? please advise. thank you.

[desert]

1 or 2 mph on your speedo, no difference in shifting.

[ckrimits]

thanks for your input