We've been running E 85 and E 90 fuel both on the street and in drag cars for a number of years, works great!!! Easy to get away with 12.5 CR on the street, been as high as 14:1 on a couple of big inch engines. Big thing is getting the curb reworked to handle the increased fuel required. Can also run a bit more total advance and when cammed properly can bring the advance in quicker and have total advance in at a lower RPM.... If you go with a bit of NOS with E-85, it takes a bit larger jet on the fuel side, too....