On the UC website, they publish the 25th-75th percentile UC capped weighted UC GPA ranges for admitted students which would give you a better indication of where you stand.
http://admission.universityofcalifornia.edu/freshman/profiles/index.html
The ranges and %admit rates are published on this website and I would not treat a 3.40 the same as a 3.79. Also none of these admit rates are major specific but an overall admit rate so highly competitive majors will be lower than posted.
There is no drastic difference in a 3.79 vs 3.82, but when 6 of the 9 UC campuses have average UC capped weighted GPA’s above a 4.0, every grade point helps.
https://www.universityofcalifornia.edu/infocenter/freshman-admissions-summary