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<DIV>Ed, I observed the same thing about the OS header flange not matching the
exhaust port so I ground it out to match the engine but did not observe any
improvement in performance. I have switched to the Macs header because of
the O-ring wear issue. I did like the isolation of the engine from the
header by allowing it to pivot on the rings but you always know it is time to
change the o-rings when you start getting some blow by. </DIV>
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<DIV>There was some short comment about a better way to support the OS type
header and increase the o-ring life (I think it was here on the discussion
group) some time back but I can't remember who it was.</DIV>
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<DIV>Don</DIV>
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<DIV>Don AtwoodIn a message dated 10/7/2005 7:17:39 P.M. Pacific Daylight Time,
ed_alt@hotmail.com writes:</DIV>
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<DIV>Just wondering what the opinions are re. the best header for the OS
1.40. I've got the OS version and it's a bit of a nuisance to deal with
the O-ring going bad. Also, it really looks like it would result in improved
gas flow (more power) if the inlet for the "matched" header was the same size
and shape as the exhaust port. I'm tempted to grind it down to get that
match right. Has anyone done this and does it help?</DIV>
<DIV>Thanks</DIV>
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<DIV>Ed </DIV></FONT></BLOCKQUOTE></DIV>
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