Not sure on the 12 (pins maybe?), but a while back (I think it's when everyone was talking about Ramos going undefeated in CHA), I did deep dives into the careers of some of the all-time great Hawkeye wrestlers to figure out who they lost to. Here's what I found on McIlravy and his "official" 3 losses:
Freshman year: Loss in his CHA (and starting lineup) debut in the NW dual to Paul Andreotti, Lost to Dan Spilde of Wisconsin 4-2 in Big 10 finals.
Sophomore year: Undefeated
Junior year: Loss to Steve Marianetti in the NCAA Finals
Senior year: Undefeated
One comment on his losses. 2 things lead me to think he had another loss prior to being pulled out of redshirt:
1) I ran across a February 1993 article in the Daily Iowan which noted he had a loss prior to his first varsity start) but I have yet to find out who that loss was to
2) Gable's recent book "A Wrestling Life: The Inspiring Stories of Dan Gable" he has an entire chapter on McIlravy's freshman season. When talking about his decision to pull McIlravy out of redshirt, he wrote the following: "McIlravy was already proving himself as a redshirt wrestler. The freshman had a record of many wins and a couple of losses against much of the same competition the Hawkeyes had seen throughout the season."
Normally official records don't include matches while redshirting, but since he came out of redshirt his freshman year, I would have thought his entire freshman record would have counted. One other note, the TV broadcast of the NCAA finals showed his record as 21-2 (i.e. the 2 official losses listed above).