Replacement Exhaust Flappers?

[smitty214]

I have a 2002 Mariah with a 4.3 S/N 0M079100 wanted to confirm this is the right part number 807166A2

 

[stonyloam]

It looks like there is a different part number depending on wether it is a one or two piece manifold I think this covers your engine: http://www.mercruiserparts.com/4-3l-gen--2-bbl-gm-262-v-6-1998-1 A1 vs A2