SAT/ACT Dilemma?

Ok so I’m having a problem picking whether to send in my SAT or ACT scores. I got a 2120 on the SAT and a 29 on the ACT, so I know that my SAT score is relatively better than my ACT score. However, if I send in the SAT, the admission offices are bound to see my SAT subject test scores as well. And to be honest I completely BOMBED them. I got a 670 on math 2 and A 570 ON BIOLOGY(in my sad defense, I went in sleep deprived having zero prep and took both on the same day, but anyways). So I’m not sure which to send in. I’m applying to the UC’s and also I’m really hoping to have a chance at Cal Poly Slo, which I know prefers ACT. So which one would you guys send in?

Or should I send in both to my schools? I heard that the UCs look at whichever scores make you look the best if you submit both; can anyone confirm?

Can you send your SAT I and ACT to cover the requirements?

I reccomend finding out if you may do what @happy1 has suggested

Well, I don’t think the UCs accept score choice though, and they “recommend” taking subject tests for people applying into my major. So would it hurt me if I did bad? I could just submit the ACT I suppose, but my SAT is higher relatively. Hopefully if I submit my entire SAT score report they could give me brownie points for honesty?