Should I submit my ACT or SAT scores?

<p>I did about equally well on both of my tests last year (junior year) so I'm not sure if it would benefit me to submit both or just one. I'm not sure if this would play a factor, but I plan on majoring in a STEM field.
Here's my stats:
October ACT: 35 in reading, 35 in writing, 34 in math, 36 in science, 9 on essay, composite score of 35
June ACT: 35 in reading, 35 in writing, 36 in math, 32 in science, 10 on essay, composite of 35
March SAT: 690 in reading, 800 in math, 800 in writing, combined 2290
My main concern with ACT is that I wouldn't know where to send both or one in. Although I got a 35 on both, I had a solid 35 on my first try but with an essay of 9. On my second try, I barely got a 35, but I got a 10 on the essay. So if I were to submit ACT scores, would I submit both or just one?
My main concern with SAT is that my reading score is so much lower than the other two. Does that lower my chances significantly?</p>

<p>Thanks for your help!</p>