[Oldsguy]

You shouldn't have any trouble with 15 inch as they were used back then. The wheels were between 7.5 inches wide and 8 inches wide depending on the car and the style of wheel. I have no idea about the 17 inch rims. I would think a good tire and wheel shop should be able to help you find the largest size tire/wheel combo that you could use safely. I think I recall reading some threads over at Realoldspower.com about this about a year ago. You might want to go over there and do a search. I am quite sure you will find some goodies there.