Hi Marshall,

Pardon me.  Can we back up a bit.  Can you see where the leak is?  I would be more suspect of the donut where the header joins the exhaust pipes. I'm not sure how loud it could get if one of the tubes were open.  You should be able to see it. I think. If so, pinching it off sounds possible.  I'm not a pro so, mostly thinking out keyboard.

Keith 


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Nobody ever waves when I'm driving the Explorer.
K Woody

This same shop re-did the exhaust from the manifolds back just a year or two ago and everything still looks shiny and good.  The doughnut area is the first place I looked, but everything looks good and it's not quite loud enough for that.

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I wanted a Corvette my whole life, but I never dreamed of all the wonderful people I would meet because of it!

The air injection tubes can indeed rust/corrode thru where they go into the manifold, or anywhere else. They are right about getting the tubes off without damaging them....it's dang near impossible, especially if the dang things are already corroded thru. I have one of the tubes on mine that the very end had corroded off, and it would not seat properly. While I had the engine out in '99, I massaged the tube to where it would fit down in there a little farther, and so far, it has held up quite nicely.
IF you decide to eliminate the tubes, you will also have to eliminate the rest of the AIR system plumbing, or the smog pump will eventually lock up.
I believe there is at least one place that sells replacement AIR tubes. Depending on how bad yours are, you may need to also replace the manifolds, or you may not. Those tubes actually go down into the manifold, into the exhaust stream, so they get kinda funked up, and can be a real pita to get out...


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Joel Adams
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[QUOTE=Adams' Apple]I believe there is at least one place that sells replacement AIR tubes. [/QUOTE] Do you happen to remember that place's name?

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I wanted a Corvette my whole life, but I never dreamed of all the wonderful people I would meet because of it!

Try Bairs Marshall, they had lots of manifolds there awaiting a new owner......

About a year ago I had a pesky exhaust leak that I couldn't figure out.

Turned out the studs that hold the donut between the pipes and the manifolds needed replacing. (They had been worked with in the past due to installing the true duals.)

Just food for thought as you (or they) begin to dig in to it.

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ems nice uns.....

Gee, Albo....ya couldn't let Marshall in on WHERE you found those? What a pal!

Corvette Specialty has those, Marshall. No...not our Larry's Corvette Specialties...it's a different place.


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Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

I'm blessed with a '76 L-48 -- No A.I.R. system right from the factory.  For some reason I guess GM got past EPA that year without that system.  I think the L-82's had it, though.  Good luck solving your problem -- do you have to pass any emissions?  If you don't want headers (like me) you could just get a pair of rams' horn manifolds without the holes and bolt 'em on.  

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Thanks guys.  I will try both

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I wanted a Corvette my whole life, but I never dreamed of all the wonderful people I would meet because of it!