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I looked into my exhaust manifold on my 1977 280Z and saw the inside chambers rusted/blown through. I'm thinking this may be why my exhaust sounds so uneven at the tail pipe while the engine purs like a kitten. My question is this; can I swap a 78 or 76 exhuast manifold into my 77 without any tweaking? One more thing, what adhesive should I use to glue my hatchback weather stripping down? Opinions welcomed!
 

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I know what WON'T fit!

any of the ZX manifolds! They have the wrong headpipe angle, and if you try to swap the late model headpipe into the early car, you end up having to bang the **** out of it to clear the laft T/C rod mount.
Take a look at the manifolds, I'd say they should be similar. If not, it's nothing more complicated than taking the appropriate headpipe along with the manifold, as the Cat was in the same spot for all years 75-78.
For my weatherstripping I used 3m "Weatherstrip Adhesive" They have yellow snotty looking stuff, and some black stuff. I prefer the black; it's heavier bodied and doesn't string all over the place when you lay it down. Plus it really doesn't show on the stripping, including when you glue pieces together to make your own custom piece!
 

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The answer is: It depends...

In 1977, the 280Z went to the N47 heads, which had round exhaust ports with a liner. Earlier heads had rectangular ports. The exhaust manifolds are NOT interchangable.

You need to first determine what your head requires (maybe someone changed it along the way) and find an exhaust manifold that matches up. One other thing to consider is the EGR tube. Make sure it is the same configuration as yours.

The bolt pattern should be the same on all of them.

Tom D.
 

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I disagree!

I currently have an early-model N42 exhaust manifold on an N47 with the round ports and exhaust inserts. You just have to run the late-model exhaust gasket, the Square port manifold is larger than the flow path area of the round port, and the gasket seals just fine.
The port configuration is correct, they do change, but that is not a problem in this case.
 

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Now I'm confused???

Tony

Are you implying that you could use a square port exhaust header with a square port manifold gasket on a round exhaust port head and not end up with a leak?

If this will work then why did they bother to make two different styles of headers in the first place?

I have always wondered about this, since even the square exhaust port heads end up going into a round tube at the header flange.

Wayne Monteath
Masham, Quebec.
 
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