Nope, B is a 3,no +or - at all. A=4,B=3 and so on.
So admissions stats aren’t that different but things still look good for you. LSA is 3.9 unweighted with 32-35 Act avg. Engineering is 3.93 with 34 Act.
So your instate plus nice rigor in your courses and great SAT score. Michigan also wants to know you want to be there. Go visit, do an official tour, ask your AO something you can’t find on their website.
I like your other school choices but Cornell and Stanford are reaches for everyone like Michigan