I can tell you what a friend of mines weighed. He had a dual 4 set up with an aluminum intake and a built up C-6, which added weight, but his weighed right at 3,200 pounds. I don't remember if he ever brought it down and had us weigh it for distribution when we were setting our cars up or not. But from driving it I would guess it weighed more in the front by a fair amount. Don't forget the C-6 added quite a bit of weight but maybe this will give you a starting point and some of the guys that have them set up right can tell you more.
Ron
