ND and Clemson played 4 common ACC schools. Considering the games were played at different points in each teams schedule and that ND was a team in rebuilding all year, the results in comparing common foes is not far apart. The only team of stature outside of the ACC that Clemson played was Texas A&M who almost beat them, and then faded from national contention as the year went on.
I would say the spread presently should be one TD and either team could win the game with either a good performance or a turnover at a key point.