Unless you rejet the carburetor a bunch richer, E85 will run lean enough to burn holes in the pistons, melt the ground electrodes off the spark plugs, burn valves, and do a lot of other really nasty things to the inside of your engine. If you stop after a few miles at highway speed and open the hood quickly, you'll probably see that the exhaust manifolds are running red hot. E85 is so much lighter weight than regular gasoline there's no way to flow enough of it through a carb jetted for gasoline to perform right.
Jerry
