Should I take the SAT if I did bad on the ACT?

I have taken the ACT twice and I got a 27 then a 29. Should I take the SAT and see if I do better or take the ACT again? I seem to do well on Collegeboard tests like the AP tests (I got a 5 on one and I think I did well on 2 I took this year) and the SAT is from the collegeboard. Also should I take the subject tests if I want to apply to Notre Dame to increase my chances of acceptance since my ACT score is too low.