Tire size

Hello Moparistas,
I have a question for you, what size would you use for a rear tire on a 1964 Dodge Polara? The rims are 15x7, I have Hi-Jacker shock absorbers (the car is raised a little at the back because of this) now I have 275/60 ​​r15 rear tires, unfortunately when someone is sitting in the back seats and I drive over a pothole, the tire cuts slightly on the wheel well, mainly towards outer part of the fender. Wouldn't it be better to use 255/60 r15 tire dimensions?
Thanks in advance for your answer!
George
Author: Jiri Deak