Trouble deciding when I should take Sat II

Hey guys, so I want to take Sat Subject Tests for Us History and Chem since I’m already in APUSH and AP Chem, but I took a practice test and I scored 640 on both of them and I really only have two tests dates left which are June 1 and August 24. I am debating currently whether I should just take SAT instead for June 1 and then take an SAT Subject Test August 24, which would give me enough time to study for SAT Math 2 as well because I wanna major in STEM, but I am also afraid that I might lose all my knowledge over the summer on chem and us history. I have only taken the SAT once and previously received a 1420. Should I wait to take the SAT Subject Tests and attempt to study over the summer (including Math 2)? Or should I just take it June 1 since I have already studied for US History and Chem APs and not take Math 2 at all because I want to have the remaining months be SAT test dates?

I would take the SAT II USH and Chem on June 1. It would be a good idea to review some of the concepts that are not covered in the AP material over the next month before the June test date. For example, people tend to stumble upon the relationship analysis section in SAT II Chem since AP Chem does not have those types of questions. For the SAT II USH, they tend to ask really factual questions (i.e. ones that rely purely on memorization rather than analysis). You probably want to go over that as well since APUSH relies heavily on MCQ’s that rely on some kind of analysis. Then, over the summer, I would study for the SAT, if you’re planning to retake it in August. Hope this advice helps out!