Be sure to go to the bathroom at the beginning of the day. If you just ate 3 lbs of pasta, you really don't need that to be passing through during the ride.
If this is an organized ride with scheduled rest stops, you can get by with 2 bottles. If you are self supporting and stopping halfway, consider putting heed in 2 bottles and water in the others just in case you get sick of the taste of heed. Since you will be stopping, I think it might not be a bad idea to carry much less food and get more of that at the halfway mark too.
Since you are carrying food, don't mix the heed too strong -- otherwise, you won't be able to absorb the calories you ate and you can expect an upset stomach late in the ride.
But no matter what you do, I think you'll be fine.