...The advice to keep your heart rate down on climbs is good. You can get trashed pretty quickly by charging hills.
+1. It's a big ride and there will be plenty of faster folks passing you on the climbs. Just keep your HR down. The one climb later in the ride, Ink Hill I think someone mentioned, is a bit exposed so make sure you keep hyrdrated. With the tandem it's especially important for me to use a Camelbak since on sustained steeper climbs (10%) it can be hard to grab a bottle to drink.