My friend has 2 of the merc 350 mags fuel injected in his boat. We are replacing one of the motors with a long block and need a new intake manifold. However they are not available anymore. Has anyone run into this? If so do you know what other merc intakes may fit or something aftermarket? Thanks in advance

Is this a 300 horse 350mag with multiport fuel injection or the 250 horse with a TBI unit on the carburetor style intake and if so, 2 barrel or 4 barrel. More info is needed here.

Sorry about that. It's the 300hp mag motor with multiport fuel injection

Since the engines need to match, I would look for a good takeoff. I don't think you will find an aftermarket version, although someone else may chime in. Between the swap shop/wanted on here and on facebook, it shouldn't be too hard to find one.