I run the 255/50/16 and my wheels are offset the same as the GNX!! I added GNX flares also!! No rubbing issues, of course I got a bumper sticker that says
NO FAT B!T€$@@!! lol
How tall are the 275/55s?M&H 275/55/16 DRs. I run a small 3/16" spacer and on Front GTAs they don't rub the frame and I haven't rolled the lips. It had variable rate springs and it was high enough it didn't matter if the lips were rolled or not, I changed them out for regular springs and the tires tucked in the wheel well some. I want to swap to the 17"x9 GTAs when/if I get the GN running again and plan to use 275/50/17 M&H, just hope they fit as well as the 16"