Bought a new vacuum pump for my '87 300SDL. Also bought a new gasket for it, both thru Pelican Parts. Upon opening the box, I see that the pump came with a gasket that is metal and part of it is filled in to help pool the oil I suppose. The gasket I bought is just like the one from the old vacuum pump. The gasket that came with the pump is a little out of shape and has a crease in one part. I am thinking of going with the gasket that I bought separately.
Does anyone have advice for me?
Thanks

I would go with the one that came with the pump. Not exactly sure how it works (the pool is below the main working parts of the pump), but it's supposed to extend the life of the pump. If you use the metal gasket, you need to remove the timing basket, or the bolts will interfere. The basket is only used for alignment during assembly, so it can go. You'll understand what I mean when the pump comes out.

If you decide not to use the metal gasket, I'd be interested in acquiring a spare.

Maybe the additional pocket can catch loose bearings on failure of the vacuum pump? Perhaps it might be a good ideal to use the newer gaskets on existing pumps if this is true?

I might use a little bead of good gasket sealer/substitute in the creased area of the new gasket if it were mine for installation.

Thanks to both of you for your replies.
PH