Hey, in 1975 and 1976 we played LSU, Indiana, TCU and Miami.
Of course, TCU went 1-10 and 0-11 in those years, and was utterly non-competitive in the Southwest Conference; LSU went 4-7 and 6-4-1 (and tied Nebraska in 1976); Indiana went 2-8-1 and 5-6; and Miami finished 2-8 and 3-8.
Those might sound like major programs in today's landscape, but they were cupcakes in the day, along the lines of Kansas since Mangino's departure.
In those days, the top 2 or 3 teams (Nebraska/Oklahoma, Michigan/Ohio State, UCLA/USC) in each major conference tended to be much, much better than the rest of the conference, and the dregs in each major conference were absolutely horrible.
Other than KU and possibly Oregon State, there are no major conference cupcakes. Look at Colorado. Yeah, they were 4-9 and 1-8 in the Pac-12, but they came within just a few points of beating UCLA, USC and Utah. Even KU and Oregon State rose up this year and nearly defeated TCU and Oregon, respectively.
All of this is to say that comparing schedules from 35 to 40 years ago to today isn't remotely possible. College football has changed too much.