This subject has been hammered countless times here... some of the data from PG and others are great. But agree with Pia Ump for short, quick answer... "80's" gets you somewhere when it's the kind that you know it when you see it.
There are always stories about guys in 70's and they are true. But here is a twist on those guys that doesn't often get discussed. I think that most of those guys were not recruited as P's. They did something else as a position player and due to a variety of possible circumstances, they got thrown into the P mix (emergency need, mop up, extensive tourney, rainouts force several consecutive games, etc.) and were able to get guys out. So they got rolled out again until they can't get guys out... Or, they are P's and get hurt and don't reach their projected velo so they re-invent themselves as a side-armer, spotter or junker. But again, they were not recruited to be a 70's P. It is not a number that you shoot for and say, "hey, I can throw in the 70's so I can make it as a P on a college team". Just doesn't work that way.