What is the tallest tire I can run on a factory 18" wheel? (2011 C

[OUSux]

I want to get the tallest tire I can run on these 18" stock rims, not worried about width, but fill up the wheel well. I want to replicate this black Tahoe, tires like his, and that stance, but on this white one. Would you go with 275/75r18s or 33x10.50s? Or what tire size? Thanks in advance.

[Big Whiskey]

A 275/70/18 would be quite a bit taller than stock. They're over 33" tall. I don't think those Tahoes have a whole lot of room to work with in the fender wells.