I think your tires should fit fine. However, you did not state if it was front or rear. I am pretty sure that I can get 275/50/16 on the rear of my 68 Mustang. I ran out of money before I could.
Up front I have 225/50/16. It looks like I could of gone with 245/50/16, all that I would have to do is probally roll the fender lip.
It is all in the backspacing of the rims. I think I have 4.5 inches of backspacing up front. I would suggest to get the wheels from a dealer that will let up play with it, and if you do not like them they would let you take them back. I hope this helps.
the offset of the rim will also be something that should be considerd. on my 1965 fast back I run a 245/45/16 (the 65 has less tire clearence than the 67) now that is on a 4.5" back spaced rim. I guess what I am trying to say is with the right rim it will work chris and his 2 cents