Ok i know use the search feature, and i have but everybody seems like there saying each one is better than the other. So here is my question I have an 07 prerunner 4.0 and i want a DEEP LOUD exhaust. Which is better the Flow 40 or 50 or is it some other brand. I also heard and saw on youtube that 'cherry bombextreme' were loud. So please help and tell me what you have and if you like it and if its LOUD. Also did it hurt or help gas milage, and did you run single in dual out or what? Thanks for help.