Tilt or non tilt? I used a 69 bearing for my 68 non tilt column. I had to do a little sanding on the plastic housing if I remember correctly. Very easily corrected.
Just went and checked on an old thread. The pictures are gone but I stated that I used a little drum sander on a dremel to take a few thousands off of the inside plastic sleeve. Like stated above it was a few minutes to make the change and I would rate it as a1 out of 1-10 on difficulty.