STACKS!!
I Believe when your doing stacks depending on Dual Or Single You either have a Y pipe or single pipe conecting to the big long chrome,black,orblack Chrome stack with no tip past that you jsut pick your design of stack and diamiter and I think the 6 inch is the best whistle
i love my single stainless 6inch and there is no other people around with stacks that sounds as good as mine or as deep of a tone as mine they all have dual 4 inch around here its just what ever your heart is set on.



