WHEN are you doing this ride? How soon? How much time do you have to train for it?
How many days long is this tour? You said: "I'm riding a 90 mile tour with rest stops every 10 to 15 miles" Is that 90 miles a day for a week? Two weeks? Or is the whole tour 90 miles, but you are covering that distance in 3 days (30 miles per day)?