275/60/20 On 20x8.5 +25 Offset Rims W/rc Level

[MB2008LTZ]

Will they rub? I have a 2008 LTZ with the factory mud flaps and 275/55/20s. I know that the factory rim is +31 offset. I bought a set of MB Gunner 6 wheels 20x 8.5 with a +25 offset. I just put on a RC leveling kit and think it looks just fine, but I was thinking about ruuning the 275/60/20 on the Gunners. I just don't want to remove my mud flaps. How much would the size change affect my speedometer? I'm ok with the stock size, but if I can fit the 275/60/20, I might go with it. I plan on running the stockers in the winter and the Gunners is the summer. Thanks.

[blackout07]

My bud just put some 275/60 Cooper Zeons on some 20x8.5's (+18 offset), with a 2" RC and there is some very minor rubbing on the rear of the fender well. The mud flaps may be an issue.