Okay, so I finally had time to pay attention a bit and research a bit more. By changing my tire size from 265/60/18 to 275/65/18 I would be going from a 30.52" tire to a 32.07" tire (DTD online calculator) with my 3.31 gears. By doing this I am effectively changing my gear ratio from 3.31 to 3.15 (Wallace Racing online calculator).

I do have a question though......I see a lot of 2009+ F150 4x4s, (again my truck is 2wd) and I have had the chance to speak with a couple owners and check their trucks out. So far I have seen 4 that have the 3.31 code on the door sticker as well as the 275/65/18 tires size on same door sticker. Shouldnt their gear ratio actually be 3.15 like my trucks would if I do decide to change the tire size?

Through using the calculators, there is also one available that tells you what gearing you need to effectively change the tire size and replace gears to keep what you have now. For fun I punched in all the numbers just to see. With the jump in tire size I am aiming for, I would need 3.47 gears to keep the 3.31 final ratio. Does Ford even make 3.47 gears to install in above mentioned 4x4s to be able to honestly say that the final ratio is 3.31? This is just thoughts jumbling around in my head, but would make one think.