Prepare for ACT or SAT Subject Tests?

Hello! I am a rising senior who’s freaking out about the whole college admission process. So here are some basic stats about myself: 1530 SAT, 3.83 UW, 4.11 Weighted GPA, 17% in my class. I have the ACT on July 13th and SAT 2 tests in August, and I am planning to take the Chemistry, Physics, and Math II tests since I want to be an engineering major. On my last ACT, I made a 32, but I am working for a 34 or above since I want to apply for very competitive colleges. My time is very limited because I have tons of extra stuff to do(working, school summer training that lasts from 8-4 every day, volunteering, college essay workshop, etc). Which test would you say I should focus on right now in order to maximize my admission chances?

Thank you so much!

Why are you sitting the ACT with a 1530 SAT?

Because I chanced myself on Prepscholar and let’s say if I get a 35 ACT, which is equivalent to 1530 SAT, my chance at most universities is about 5-7% higher than that with a 1530 SAT. Is that true though?