>Ken,
 Good luck on your proposed flight to Hilo. Oakland departure with advanced
notification should clear you for a direct departure out the bay to the
ocean. Suggest take off at first light. At your max gross you should clear
the bay bridge easily. The altitude you need will depend on  the weather and
on your proposed altitude.

You can guarantee you will have scattered to broken cumulus, the bases will
be 1500 feet tops 3500 feet. The winds will most likely be from the west 15
to 20 knots. Should your winds be under 10 knots, then smile because someone
up there loves you. If there are fronts you must cross then all wind
projections are up to your weather briefer.

I have made the crossing from Navy Alameda to Navy Barbers Point on Oahu at
lest six times. True it was in a twin engine jet, one pilot ,one radar
Navigator and one third crewman. There are a lot of white caps to see and
mostly nothing else. My log shows one hundred  sixty nine pacific crossings
with none of the fancy electronics.

With a little advance preparations your plane and you should do just fine.
You will need an HF com set for long range contact with air traffic control.
Do not be late on your reports else they start to look for you.  Rent the
radio. What will your fuel burn be, and what will your true air speed be
while you are trying to cruise during the time that your weight is three to
four hundred pounds over weight??
Warm regards, George Lee