getting new wheels and tires.

[barrow454]

I'm about to buy a new set of wheels and tires on my stock 2011 Chevy Silverado extended cab. I just need to know what lift i will need to be able to fit 305/55R20 tires on it

[Jsdirt]

275/55-20 is the stock circumference, just slightly wider - that 305 tire is only 1.3" in diameter bigger, divided by 2, is less than 1" higher than stock. Probably no lift needed. That added circumference will slow you down, just as lowering the numerical gear ratio will (going from 3.73 to 3.08 for example). You'll turn a slower RPM at any given speed, but give up a little off-the-line grunt, and towing capacity.

 

The main problem will be rubbing in turns, as those are just under 1-1/4" wider than the 275/55-20.