I took the ACT in the early 80’s. I took no prep course or did any preparation other than getting a good night’s sleep the night before. I wasn’t in the academic elite in my public high school (HATED high school,) and yet, I still scored high enough to earn college credit for English and science.
I took the ACT in the mid 80’s. It was harder than the SAT which I also took. I took it twice and did slightly worse.
Looking back, I would say the ACT validated my inward suspicions that if the truth was known I was never college material to begin with although I did somehow manage to graduate and get the degree even while battling what was then a debilitating medical situation.