I buy my E85 from Forged Fuels. 4 bucks a gallon. I run a Horsepower Innovations carb. Do lots of research. When I bought mine Mark Sullens E85 and Horsepower Innovations seem to be up top for custom carbs. There's a handful of decent builders now. I haven't heard much good about Pro Systems for E85 but I also have zero experience myself with them.