I remember Ohio State was a 58 point favorite over Northwestern in 1980, they won 63-0.
If you do the parlay it is a bad play IMO because you are getting laying an extra 11 points and getting +260, when it should be +360. It is highly unlikely that Baylor scores, I actually like Oklahoma and the Under here, I think it will be 56-0 or 63-0. IF Baylor does score 7 then Oklahoma has to score 63, and if Baylor is busy scoring 7 that proably means Oklahoma wont have time to score 63.
I think Baylor for sure scores 0, and Oklahoma has a 75% chance of scoring less than 64, so you basically have a great middle here. Take Oklahoma -52.5 and the Under 64 and you have yourself an 11.5 point middle.
I hit a middle like that in the Little Leauge Worldseries. I knew Mexico would not score vs Japan and Japan was giving 4.5 and the total was 9, sure enough I won both when Fushachi Muchi Little leauge won 7-1.