dart headers

I can appreciate that,also its a pretty unique deal when your racing with limits like you are and as crackedback said step headers work in a very small window so if your in it they could be of some benefit.I would be skeptical though of any increase over low,low teens for h.p. and only in a small rpm range and they defintiely do not flow as well as a true 1 3/4 header.Step headers were a fad long before tti had them and their pitch was the torque of a 1 5/8 tube while still maintaing upper end h.p. but we all know there is no free lunch.I know of alot of small block cars running 1 5/8 and running very well,12s to 11s,now these are cars that have ported heads ect but run on 3.55s to 3.91s so they are street cars.Ive found alot of it is based on cubic inch and rpm range,there is at least one calculator I stumbled across on a circle track site that seemed to coincide with what Ive experienced.I wouldnt run a 1 3/4 on my 340 in its current form (approx 420-430 h.p w/6,300 shift points) since in my experience it wouldnt add any overall power and minimal if any afect on e.t.s,but this could also help explain why tti elected to do a step tube design simply to try to acheive a happy medium.At any rate its hard to beat a straight 1 5/8 or 1 3/4 since in the proper application either will make more overall power than a step tube design.