I ordered a melling pump for my 454
Mag and it did not come with a gasket. Did some reading and though they sell gaskets for them I read they should not be used. So I checked the witness marks on the block and oem pump and it does not look like a gasket was installed. So gasket or no gasket? Thanks!!!

No gasket is used, but there should be an "O" ring between the pump and the rear main cap.

I did a short block rebuild at the local machine shop and the URL you have me is not coming up. So I assume that the o-ring is installed and the mating surface between the pump and motor does not need an o-ring?

http://www.mercruiserparts.com/Show_...sp?dnbr=804807 99&ivar=images/COMMON/20119.png&inbr=4854&bnbr=170&bdesc=Cylinder+Block+ and+Camshaft

Try this link...

I feel like a technical retard - looked at the 454 Gen IV diagrams and don't see a o- ring!

So I can't even find a gasket number - just some odds and ends gaskets available on the internet. I looked and there is not any groove for an o-ring so that does not seem like it fits my application. Anyone have any additional advice on this??

no gasget or o ring is used on any gen of bbc for mounting the oil pump,NONE

mike is correct NO GASKET +++NO ORING bolt it on and your done

Thanks gentlemen!