More like East and West, actually.
http://www.politico.com/2012-election/map/#/House/2012/CA
Now yes, Orange, Riverside, Ventura, and exurban San Diego can be somewhat Republican.
28 Safe Rat seats, 10 lean Rat, 2 lean Pub (could put 31 Gary Miller into lean Rat), 13 safe Pub seats.
Possibly you could do 3 states...Rats would keep their +2 advantage in the Senate. LA-Orange-San Diego would be one (Rat) state, then the north coast would be another Rat state, with the interior being the Pub state.
In exchange for getting some Republican territory in Orange county (which would be outvoted but pay a disproportionate share of taxes), maybe Democrats would allow the 9th circuit to be split up.
10 more Dem Senators, just great