1970 I6 200, IMCO or non IMCO

I'm trying to get a new exhaust manifold for my 7o Maverick with with a 200ci 6cyl in it but end up getting two options one manifold with IMCO and one without. What is it and how do I know which one I need to get? Not many good pics out there. I only have one little tube going to the carb that I believe is for the choke.

thank in advance

 

i give up - watz an IMCO ?
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the '1080' img is of the later years - much larger runner exh. manifold.
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Early tubular shaped manifold has smaller runners and smaller exit port ... also cast ear is broken off.
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here's a vendors illustration and description

https://www.npdlink.com/search/products?search_terms=exhaust+manifold&top_parent=200001&year=
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or:
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Hookers:

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CL $75 find

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have fun

 

In your first pict, the large flexible hose is part of IMCO system.

IMproved COmbustion

 

I thought that was just a preheater hose and the small tube was for the choke. Not much attached to this manifold. This would constitute being IMCO?

 

If you really want improved combustion, swap in a V-8...

 

IMCO is the heated air cleaner, a lean carb & probably retarded timing.

 

Get a new repop for an early (1960's) Mustang. It will work.