I didn't do anything to the fuel system on mine when I turned it up. It's been a real long time, but IIRC, it didn't take much of an adjustment either. It seems like it was a minute adjustment that I made and wound up having to back off of that. I had a Banks Sidewinder turbo on it, 4" back exhaust and a Transpack. It would tow real good. I don't know what is available for these any more, but I would consider trying to get it more air way before larger injectors, JMO.