quote:Originally posted by Bosswrench:
FWIW, engine builder & author David Vizard has written about headers several times in his various books, and according to his dyno tests, if the individual tube lengths are within about 6" or so, no power gains/losses will be seen. What's more important is the fit of the individual tubes into the weldment. Sloppy tube fits buttered up with weld do not work as well as neat fitting 'fishmouth' tubes, and often crack. Further, mild steel tubes will expand and contract by as much as 0.060", and stainless even more, which is really what cracks poorly made headers.
I'm not arguing and actually like that statement.
Putting headers on my Shelby, I wound up with a choice of Hooker Comps or Super Comps.
The Comps are not equal length. The Super Comps are.
Hooker claims the difference is 3% at the top.
In my case the difficulty of installation with the equal length increases exponentially.
Equal length were 34", the unequal short tubes were 32", long 34".
I'll go with Vizard. I like the guy already.