If I am following correctly. You just need an exhaust donut gasket to seal the outward flares of the manifold and down pipe.
This part number 1074921409 may work for you, if not then go to your local exhaust shop and have them match up a donut for you.
http://catalog.peachparts.com/item.wws?sku=W0133-1634496&itempk=80688&mfr=Bosal&weight=0.37
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