215-75/14 or 205-70/14 ,, both are pretty darn close,, see these sites http://1970mgr.org/_Tiresizes.htm http://www.turbinecar.com/tires.htm or google "f70-14 metric equivalent"
Actually, it's 215/75-14 or 225/70-14. Both are about 26.5" in diameter. The F70-14 was 26.2" in diameter. A 205/70-14 is only 25.3" in diameter. The 225/70 is about 3/4" wider than the 215/75.