What size tire will fit without rubbing or needing to cut?

Hey everyone, I’m getting ready to lift my truck and get new wheels/tires for it. I currently am running 18in stocks on stock suspension. I’m wanting to get the RC 3in lift (front coilovers/rear block lift) I know it’s not everyone’s favorite but I don’t want/need anything crazy since it’s a parking lot queen lol my question is how big of a tire combo can I get? Ive been told 275/65/18 is the biggest I can go with a 3in lift to get no rubbing, is that true? Or can I go to a 275/65/20?

 

Thank you for your service! The most common fitment with a 3inch lift would be 275/70-18 on 18X9 with an 18MM Offset. Or 275/60R20 on a 20X9 with an 18MM Offset.