We ran them on some of our drag cars and some nascar teams have played with them. Why has no one tried them on the Lightings yet. I think they will work if we can get someone to build them.
I had to make my own in the past but I had the time and room under the hood.

 

They are available from JDM/Kooks. The tubes are 1 5/8 X 1 3/4 with a 3" collector.

I think stepped headers actually work in about one in twenty applications and that might just be and accident.

Seems to me they are a little backwards, as the exhaust travels out the pipe and cools down shouldn't the pipe get smaller to keep velocity up.......sorry just thinking out loud

 

Kooks makes (Or used to?) a stepped header that was 1-5/8" primaries stepped to 1-3/4" with a 3" collector..

Im not sure if they still make it or not..

I think I read that JL is coming out with a header that uses a 3" collector, I assume the primaries will be larger than the standard 1-5/8" the normal headers use...

-Dale

*edit* Doh, the other Dale beat me to the punch. */edit*

 

i've been running a stepped long tube with 3 inch collectors for over 3 years now. there used to be a company by the name of lightning performance parts that made them long before kooks ever came out with a header for our trucks.

 

Robert
I used to run those headers too but mine were not stepped....the truck ran really good with those headers.
Dale