Here is my opinion if you want. For 15's, go 215-65-15. They look really good and most likely won't rub in the front. My friend runs them on his 67 bird. For 14's, 215-70-14. I like the 14's but they are tricky with disc brakes but really are the best for 67/68 birds. There are some original Rally 2's that will go over the discs. Some will not. I had 14" AR Torque Thrust D's that I really liked but had to ditch them when I put on the discs.