No, the truck has the same fuel system as the flex fuel trucks, the lines are e85 rated and there is plenty of overhead in the injectors and pump.
I have played with it. I get better fuel economy on a 35-40% ethanol blend than I do with straight low grade gas. Here is the why: At cruise on 87 octane the truck is pulling timing, when you step up to premium and watch timing it will stay near max brake torque timing, that makes a big difference in economy. Ethanol is less energy dense than gasoline, but you are making up for it with combustion efficiency. It is not quite as good as running premium, but lets look at the economics of it (prices are near me in Colorado):
Regular 3.539
Premium (91 octane) 4.159
E85 2.49
50/50 e85 and regular: 3.019
E85 blend octane: 94
94 octane is costing me $0.52 a gallon less than regular gas, and a full $1.15 a gallon cheaper than "premium" 91. I see about the same fuel economy in town and better on the highway than I do with regular. The truck NEVER pulls timing. Even if I saw a decrease in economy, I have a 36 gallon tank, I don't care. As fuel prices climb the price between e85 and premium is going to go up. The best economy I have ever seen out of the truck was 17.3 mpg on e85 blend, that is my standard morning commute and I usually see about 15.3 out of the truck on regular gasoline.
If the truck ever gets boost I will run straight e85. If I am going to be running hard off road or towing I will run straight e85. If regular fuel crests $4 a gallon I will run straight e85, it will end up being cheaper per mile. In the winter time the pump blend drops from 70% ethanol to 50%, in the winter I will run is straight.
My supercharged mustang, my coyote powered 78 f150 both run e85.
I like it so well that if I am going on a long trip I will load up 18 gallons worth of VP cans and stow them in the bed, most large cities have e85, and if you are in corn country it is common. But sometimes it is a way off the highway.
The only warning I have about e85 is the shelf life is not good. If you aren't putting a tank of fuel through your truck every 6 weeks stick with regular fuel.
All you have to do to make it work is have your tuner enable it. If you are in Colorado I can do it for you as well, the logic is already built into the PCM: