Sounds like it hasn’t happened yet but, I’ll play along… if you apply with a 4.1 UC GPA and 30 ACT, you’ll be a strong candidate at CP SLO and UCI but both schools are looking at a broader profile than that. Applicants with those stats an nothing else are rejected from both every year. At UCSD, your GPA would be a little below average and your ACT average. You’d need a strong essay, course rigor and ECs to be competitive. You aren’t completely out of range for UCB or UCLA but, would need to stand out in other ways.
http://admission.universityofcalifornia.edu/campuses/san-diego/freshman-profile/index.html
A private like Santa Clara would also be interested and may make it worth your while to attend.
If you come up a bit short of your prediction, there are still lots of great options, UCR and SDSU among them.
Good luck.