http://www.universityofcalifornia.edu/infocenter/transfer-admissions-summary
You can get a great profile of UC transfers (by campus) from that tool.
SLO updates this table each year. Note the small number of total transfer admits. Also, their preference for the local CC campus significantly skews the reported Avg GPA - For non-local transfer applicants, SLO is probably the most selective public school in CA. Lots of applicants are rejected by SLO but accepted by UCLA every year.
http://admissions.calpoly.edu/prospective/profile.html
Smart applicants use TAG to lock down a seat at UCI/UCD/UCSB as a fall back.
Do your best, follow the TAG/TAP framework and process and see where you are in a year. Your GPA and EC resume will dictate which programs to focus on.
Good luck.