I posted a list of the single-game Passing Touchdown Leaders (LINK).

Here are the Career Passing Touchdown leaders through 2023:

1. 87 - Chad Henne (2004-2007)
2. 71 - Elvis Grbac (1989-1992)
3. 70 - John Navarre (2000-2003)
4. 49 - Denard Robinson (2009-2012)
5. 49 - J.J. McCarthy (2021-2023)
6. 46 - Rick Leach (1975-1978)
7. 45 - Shea Patterson (2018-2019)
8. 44 - Devin Gardner (2010-2014)
9. 42 - Steve Smith (1980-1983)
10. 37 - Todd Collins (1991-1994)
11. 31 - Jim Harbaugh (1983-1986)
12. 30 - Tom Brady (1996-1999)
13. 27 - Brian Griese (1995-1997)
14. 25 - John Wangler (1976-1980)
15. 22 - Drew Henson (1998-2000)
16. 22 - Wilton Speight (2015-2017)
17. 21 - Cade McNamara (2019-2022)
18. 20 - Jake Rudock (2015)
19. 19 - Dennis Brown (1966-1968)
20. 18 - Dennis Franklin (1972-1974)
21. 17 - Demetrius Brown (1987-1988)
22. 17 - Michael Taylor (1986-1989)
23. 17 - Tate Forcier (2009-2010)
24. 15 - Scott Dreisbach (1995-1998)
25. 14 - Don Moorhead (1968-1970)

J.J. McCarthy ranks as the most prolific passer of anyone who has played 3 or fewer seasons at Michigan.