325 would be 12.8 inches wide. On a 20 inch rim a 60 aspect ratio would be 35.35 inches tall. A 65 aspect ratio would be 36.63 inches tall. According to the math anyway. You would need a 345/55/20 to be approx 13.58 inches wide and 34.94 inches tall. A 60 would be 36.3 inches tall. Again according to the math. Actual tire sizes could be a hare one way or the other.
What tires are you looking at.
What tires are you looking at.