1991 Mercruiser with closed cooling system.

[Earl28]

Is the solid riser gasket all that is needed or do you need a plate and two gaskets? Thank you the information. 

[fisherdude]

Here is a link to different motors http://www.sterndrive.info/sterndriveparts/manifolds.html . I have a 3.7 lx I had a leaking gasket between the raiser and exhaust manifold and it's just the gasket my motor is an 89 last year produce I don't know if it's the same on yours