on tip i give is to find your source for E85 and stick with that source. or test your content often. i just bought a drum so that i'll have enough to last. also i take plenty with me to the track.. if you are going out of town and not sure you brought enough for the long weekend research available stations before you leave.
i was told about this website and even seen it in a post on this site. it offers alot of good info.
www.raceone85.com
the guy that did my carb has done many e85 setups around here if you'd like his number pm me.