I would say go with a 215 70 14, if you want it to look close to stock. You could also go to a 225 if you want a little more width. The 215 will be wider than stock but look right.
i ran a 225 60 on my 65. looked pretty good but i was thinking it would look too small on a 69 fastback. are 14's stock on a 69? i thought they went up to a 15 by then?