I had a rubbing problem with 215-65-15’s on 15x7 r2’s on my 67. My friend ran the same setup on his 67 bird with no rubbing but his front end sits higher. I went with 215-70-14’s on 14x6 r2’s and no rubbing. 67’s and 68’s don’t have a lot of room for front tires. I think mine were rubbing on the outer wheelwells. Unfortunately whenever you deviate from stock on anything with FGF’s you can run into problems.