Looking for 1990 3.0 exhaust manifold

[Peter123!]

looking for a exhaust manifold for a omc 3.0 in a 1990 four winns.

 

[Lou C]

looks like someone forgot to drain that one!

http://www.barrmarine.net/omc.html

I used Barr when I replaced the one piece batwings (NLA) on my 4.3 with the center riser later OMC/Volvo style.

 

[alldodge]

Google "omc 3.0 exhaust manifold"
Or look for BARR-OMC-1-3858850

 

[Peter123!]

It’s like a unicorn. A replacement doesn’t exist.

 

[Peter123!]

Intake runners are different

 

[alldodge]

OK delete post, it was for 1995 and newer will look some more

 

[alldodge]

Finding its part number 986940 and see MM has it

https://www.michiganmotorz.com/exhaust-intake-manifold-1991-p-299.html

Kind of wonder if a later wouldn't fit due to similar head but will leave that to Lou and others

 

[Peter123!]

Again the Intake runners are different. Thanks for searching though

 

[Lou C]

Sierra 18-1901 Exhaust Manifold Replaces 0984054
the 0984054 is the # I got from an OMC catalog...
http://ww2.iboats.com/Omc-Cobra-Mani...view_id.221953
iboats has just one!​

 

[Peter123!]

Look at the pictures I posted and you will see the difference in the intake runners. It will not work

 

[alldodge]

It is a unicorn, but just maybe Lou's will work, or maybe even a different one if thought about it just a little more. Yours in one of a kind, I cannot even find it on the web with a part number. But if we look at what is actually needed, only the outside area needs to seal. The ports are in the same orentation.

So maybe worth buying one gasket for the newer manifold, and see if the gasket will cover the other edge. If it does, then cut away the inside

 

[Peter123!]

This is what I ended up going with. It does have the Holley carb so if the intake runners will work I should be good to go. I hate to put a lot of money in it. I’m going to sell it since I’ve only had it out twice in two years

 

[Peter123!]

Thanks for all the help

 

[Lou C]

It looks like they were trying to find a way to make it cheaper to cast, leaving the divider out between the center exhaust ports and the same for the intake ports. As long as the ports match up with what your cyl head has, it should work.

https://www.michiganmotorz.com/marine-engine-1990-current-p-69.html

look at the ports on the cyl head of this 3.0. Are they the same as what you have?