Any E85 is reliable mate tune your car to the fuel you use. I tuned my car with the caltex E85 & my car has never missed a beat! Dunno if this is true or not but I think caltex has more servos selling this stuff so id be more inclined to tune on that stuff as its more readily available.
As for 370kw on -7's id say not likely at all I would think even -9's on E85 would struggle to hit 370kw