@lookingforward - thanks for the advice.
He got a 4 in AP World History that he took in freshman year (that is the only AP allowed in freshman year). The other completed AP’s where he got 5’s: Calc AB, Calc BC, Stats, Phys 1, Phys 2, Phys C/M, Phys C/E-M, Chem, US Gov, Micro. Note that Phys C are tests only - no classes - all others are classes. In senior year 4 more AP’s and 2 dual enrollment classes. The stem course that he got bad grade is Chem (he later did well in AP chem test and also in sat chem subject test).
He is going to apply Northeast and UMd-CP in EA for sure; maybe UIUC as well.
Michigan and GT - we are still debating - they are his most important universities (among top 5 where he will be most happy to go - per him). Will decide based on how essays comes out.