Mike-
This a question most of us have faced in doing our conversions. Untill
recently, we had one choice, the traditional headers originated in
England by Ken Costello. These have been available from several sources
in both mild & stainless steel. They are marginally better than the
Factory cast iron manifolds, & not as likely to crack. Very restrictive,
though, as you have noted.
Several individuals have had custom headers made, or in a few cases,
made them themselves. I have some pictures from a show about a year ago
of some really outstanding home built, through-the-fender headers. This
is part of the problem- THROUGH-THE-FENDERS. Most of us have shied away
from cutting holes through, letting water in, etc. It is destructive to
some degree, in the eye of the beholder. Without going through the
fender, little or no improvement over the traditional header is
possible.
Enter the RV8. Now we have a factory header, that goes through the
fender. Social acceptability. Real source. Something that can be copied
at improved effectiveness or lower cost or both. The wave of the future.
$500.00. Or more. Maybe less.
Both Ted at TSI and Glenn Towrey are selling RV8 header copies. Choice
of one piece stainless or two piece mild steel. The two piece can
conceivably be installed with the engine in place, one piece certainly
can not. While the 'RV8 style header may not be ideal, it is a big
improvement over the traditional, in terms of performance. But, you have
to cut those holes.....
My personal opinion, just my opinion, mind you, please no flames, is
that for a 3.5 engine with stock or mild street cam, you will not feel
the difference in "the seat of your pants". Dyno tests will probably
show an improvement, but you will not feel it unless you race & measure
time in .001 seconds. Stay with the traditional headers, less work,
fewer problems. 3.9 engine, high performance versions, you may be able
to tell the difference, depending upon how experienced/perceptive you
are. 4.2 street motor, also marginal. 4.2 or larger high performance
need better breathing, go with the RV8. Gee Whiz Factor, you need the
RV8 in polished stainless or high gloss ceramic RED.
For myself, I am getting ready to install a 4.2 with a little more than
just a street cam in my 3.5 GT. Problem is, I already have a new set of
stainless headers installed on the present engine, & can't afford to
spend $400-500.00 on new headers, & let the stainless just sit on a
shelf. Ted, do you have a trade in policy?
Ted, if you read this, send me a template/description of where to cut
the holes. I may do the cutting while the engine is out, buy the headers
later.
Jim Stuart
2V8's, no dollars or sense
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