Tire size for easy steering

Well, I'm going to change my '69 Dart next year from manual to power steering.
After 2 major shoulder injuries, (one on each side) I tried to drive the car and enjoy it as is, but it's a pain to drive.(literally)
I have driven manual steering cars off and on all of my life including a '69 Super Bee and a '69 Coronet R/T with manual steering and it always sucked.
My vote is to change the car to power steering and never look back.
Forget all of the people who think it's ''manly'' to drive a manual steering car...