Thanks for the information. As to tire width, the widest tire that went under the pre-1969 C-bodies was a 9.00x14, which was the "station wagon" OEM size. Multiply that by 25.4 mm and that gets the modern section width.
As to wheels, either some repro 15x7 Rallys (as 1970 or so B and E-bodies had, with center caps and chrome lug nuts), some repro Magnum 500s, or some VN-501s (15x7, 4.0 or 4.25" backspacing) would look good. Whitewalls could be OEM with the Magnum 500s, but in the 14" size, back then. To me, P225/75R-15s would be a good tire size, in whitewalls, as to the diameter of the tire and how they fit the car's look. Power disc brake cars got 8.45x15s, for which the P225/75R-15 is the equivalent size. To me, any of those wheels with whitewalls would spiff things up a bit while maintaining the luxury/sport orientation of the car. I'm not a fan of white letter tires on such cars, unless they came that way OEM in later years.
Where did you find the car? Just curious.
Enjoy!
CBODY67