Have what I thought was an easy question...but it may be more complicated that initially thought. I have a F150 FX4 with a 2 inch leveling kit installed. I have 20 inch Ford rims on it and want to know the max tire size that will fit and be safe. I have been told 275/65R20 will work...but last night I was told that the max for the ABS system is 275/60R20. So, what is the max size that is safe? Thank you!