Does anyone know what the biggest rim size i could put on my truck without having to do any fender cutting, or no real modification. I have a 2006 FX4 Supercab. I saw a set of 23's and wanted to make sure i could use those and also see if i can go bigger. Any help would be appeciated

 

Size of the rim doesn't matter, unless you go over 33". What matters is the final diameter of the tire/rim combo. Without a leveling kit, you can go to about 33".

 

RIght. You should be able to fit a 305/35-24 (33x12.50-24) easily.