The majority of "stock" ford v8 engines use 19lbs/hr fuel injectors "yellow top fuel injectors". E85 likes a air to fuel about 30% richer than common pump fuel. Blue top fuel fuel injectors are rated to flow 24lbs/hr or very close to 30% more fuel. The oxygen sensor reports rich or lean based on unused oxygen leftover from combustion. The computer has no clue what fuel you are burning. The problem with this type of tuning is that normal pump fuel would run too rich after this mod. I have a 1980 F150 running this type mod. 15mpg not bad for a old 351w needing a rebuild.