If you plan it carefully (with good maps) you can keep it mostly flat through the Big Valley by staying between I-5 and CA-99 all the way to near Sac'to. I did this in a car coming south from Turlock. Used a combo of 165 and 33, with some back roads that included a little dirt. I will agree that 33 is a cool road, but don't forget the gas mask for the Coalinga segment!!! MOOOOOOO!!!!
