Tire size help

[Texas Chevy]

I have a 2018 3500 SRW with 265/75 R18. Looking to run a 12.5 wide tire on the stock rim. Is anyone running this setup or know if it will require trimming or a leveling kit? Or would anyone be able to tell me what is the widest tire I can run at this height without a leveling kit.

 

[2004LB7]

while I don't know for sure the exact width of the rims you have, I am willing to bet that it is on the bottom range of allowable rim widths for a 12.5 wide tire. this may make it very hard to find a shop willing to install them. sorry if I didn't quite answer your question

 

[Bdsankey]

I don't think OEM rims are wide enough to meet mounting width requirements for a 12.5" wide tire. You would have to measure then correlate that back to your desired tire's approved rim widths.