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Exhaust Manifold

Posted: Sat Jul 27, 2019 1:25 am
by gbsailing41
Has anyone tried to use a 4407872 79-80 4-2-1 manifold on a early 78 1800 124 spider by trimming the EGR port of the end of the manifold? I was wondering if the other ports were spaced the same as the the early 78. I am looking at going to a 4-2-1 instead as the 4-1 that is on the car now.

Re: Exhaust Manifold

Posted: Sat Jul 27, 2019 7:56 am
by friedman
The exhaust ports on 1800 and 2L motors are the same. I have swapped many exhaust manifolds on them. I usually put earlier 4-2-1 manifolds on later carbed models with the 4-1 manifolds. Be aware that 79-80 manifolds are designed to run the exhaust along the passenger side floor for the cat and early model manifolds are set to match with exhaust the runs down the center of the floor so the end of the downpipe may be pointed in the wrong direction to link up with the exhaust pipe. What I'm trying to say is that the port spacing is not the issue, the downpipe configuration is.

Re: Exhaust Manifold

Posted: Sat Jul 27, 2019 10:14 am
by gbsailing41
Thanks I have a 78 124 Calif with the exhaust under the passenger side . I am in a non test area with no solution items on so it should work. I just wanted to confirm that it would fit.

Re: Exhaust Manifold

Posted: Sat Jul 27, 2019 10:16 am
by gbsailing41
I love auto correct how it changes words for you. No Pollution devices on engine.

Re: Exhaust Manifold

Posted: Wed Jul 31, 2019 9:30 am
by vandor
friedman wrote:
Sat Jul 27, 2019 7:56 am
Be aware that 79-80 manifolds are designed to run the exhaust along the passenger side floor for the cat and ...
It's the downpipe that runs over to the passenger side, not the manifold.

He could use the modified 79 manifold (80 carbed was single outlet), and a 73-74 downpipe with the stock 1800 49-state system (no cat).
He might also have a California 1978 with a cat, then he'd need the 79 manifold and downpipe.

Re: Exhaust Manifold

Posted: Wed Jul 31, 2019 9:31 am
by vandor
vandor wrote:
Wed Jul 31, 2019 9:30 am
friedman wrote:
Sat Jul 27, 2019 7:56 am
Be aware that 79-80 manifolds are designed to run the exhaust along the passenger side floor for the cat and ...
It's the downpipe that runs over to the passenger side, not the manifold.

If it was a 49-ste, no-cat 1978 then one could use the modified 79 manifold (80 carbed was single outlet) and a 73-74 downpipe with the stock 1800 49-state system (no cat).

Since he has a California 1978 with a car, then he'd need the 79 manifold and downpipe.

Re: Exhaust Manifold

Posted: Thu Aug 01, 2019 9:06 am
by friedman
yea. I had a 78 Cali spider in Virginia and my state required all the Cali model emissions stuff, including cat, to be on the car even though the 49 state cars did not use a cat. That was my first introduction to the passenger side exhaust system.