I have 205/60-13 with 6" rims on my 70 S2.
They will definitely rub on the rear inside of the wheel well and the top center of the wheel arch.
They need roughly 1/2 inch additional clearance in both areas.
They only rub when turning, worst is turning and entering a driveway.
Enlarging the wheel arch as we speak.
They don't rub in the back.
Ron