The only "news article" [1] I can find that references this mentions 0.3% of student loans were discharged through bankruptcy in 1977 [2].
[1] https://www.linkedin.com/pulse/history-student-loans-bankrup...
[2] http://harvardlawreview.org/wp-content/uploads/pdfs/vol126_s...
Seems be to be some serious revisionist history going on...