OK....after much consideration, I have decided that i am going to go with 255/60R15 on all four corners of my 71. People have told me here and other places that I should have no clearance problems. I looked at a bunch of cars at Carlisle that were set up this way also. My last question, and this just came up, my car is not power steering. Will I notice a difference in the car being harder to steer? I currently run 215/70R15.

That's a pretty tall tire at 27" diameter so steering effort will definitely increase.

I was running 265/50/15's on the front of my chevelle had no problems with rubbing. As far as will it fit? Yes. A often overlooked areais the backspacing on the wheel, as it might prevent that tire size from fitting correctly. I think on my chevelle the back spacing was 4.25"