I truely don't think you can achieve what your looking too with E85.
TORCO is the absolute easieat and cheapest way to boost your full tank.

about-----$21.00 per guart (32oz)
24oz. boosts 15 gallons of 91 octane to 95 octane can't beat that!
Generally I pay $9.50 per gallon for 105 octane here in Great Falls.
Our closest TORCO dealer is 175 miles but would like to buy a 5 gallon container this spring.
Mike