That was gonna be my next question? I am gonna call comp today, and see on a cam. I think with that head design 1 5/8 is the largest header tube I can use,and still bolt them on. I could step them up to 1 7/8, or 3/4 but I don't think that ever makes a difference. I also will have to physically lay them out to figure out lengths, and that is generally up to the truck,and the space I have. Sounds like I should see what comp says they might have something that will work great with the exhaust the way it is.