I have a few bits of advice for the new riders to this event. It looks like the typical heat will be here tomorrow so hydration is more important that ever. So, drink before you're thirsty and drink often. Also, you might want to look into electrolyte replacement such as e-caps or the like. Don't over do something new because the system might not be accustomed to the change and on that long of a ride, you sure don't want any self induced irritation. Also, you'll be burning somewhere between 8,000 and 12,000 calories, so eating is very important. It's easy with the climbing and nervousness you may feel about the ride that you won't put enough food in the system. Snack often. Also be careful about going out with a fast group in the morning. Some of these people have done this ride before and while it's tempting to go a little faster, don't. Once the energy stores are gone, you'll be in for a long if not impossible day.
Good luck on the ride. I know you have trained hard for the event.
Bob
G.O.M.A. N.A.S.K
"Either lead or follow, just stay out of the way"