Do admission officers superscore between the ACT and SAT?

I did pretty bad on my SAT (1980) but considerably better on my ACT (33 composite).

Should I even report my SAT score or will they see that I did better on the ACT and use that as my highest?

UC’s require your complete testing history from the SAT and/or the ACT. UC’s do not superscore. They will use the highest total or composite score from a single sitting.

So they consider my poor SAT and my decent ACT both?

No, they will only consider the highest score, either SAT or ACT, and they will ignore the other one The only campus I know of that Superscores between the 2 tests is Cal Poly SLO. (as in, they will mix scores from the 2).