I'm new to the forum and already searched for answers on multiple pages but I can't really find a true answer for my set up. I have a 2012 fx4 4x4 with 20" rims. I am going to get a 2" level kit so what are the biggest tires I can put on without rubbing? Will 275/65/20 work?

 

Welcome buddy, check these threads:
https://www.f150forum.com/f38/bigges...h-rims-230088/
https://www.f150forum.com/f38/new-ti...11-fx4-175225/

Summary, your good choice with 2" level 305x55x20 Nitto Terragrapplers, 33x12.5r20 general grabbers and 275/60R20 Michelin A/T2 without level.
What road you are riding? Other good tire choices are Bridgestone Dueler H/T, Toyo open county A/T, compare them at 4WOL Tires

 

Thanks for the help. I think I'm going to get the terra grappler 295/60/20 34.4x 12.3. With a 2" level they should fit nice. They are only 2.3" taller and 1" wider than my stock pirellis.