I'm slowly upgrading my (2011 5.0) stangs internals to get some more get up and go out of her. Currently have new nkg plugs, street racing coils, 47lb injectors (800cc roughly I believe). I have a basic race tune right now and am running 93. I plan to switch to e-85 soon when I buy a bigger fuel pump (dw 400). Should I upgrade my fuel rails? How necessary is it for the extra power? I'm confused at how much of a difference it would make stock vs aftermarket with oe fuel lines. It will be getting a Dyno tune also. And incase anybody was wondering I also have long tube headers (no cat, no resonator and x pipe), cold air intake, and throttle body spacer. With everything combined I should definitely get a nice boost in performance. Just not sure about the rails. Any help is great thanks! ** Side note. If anybody else has any ideas for relatively "cheap" performance mods let me know. Thinking about doing an egr delete but I see no real point other than having a clean engine bay and listing it as another mod on your car.