Riser gasket clarification please

[rick3452]

Hi guys, new 5.7 motor getting near installation. Installing new Mercruiser manifolds and risers. The ones we took off had only the two side slots open on the gaskets with small holes on each end.
My mechanic says that the gaskets should have open slots on four sides. Confused???
2000 5.7 0m012817 closed cooling
thanks
Rick

 

[Bt Doctur]

closed cooling is either "half" engine only or "full" engine and exaust manifold. this requires a blockoff gasket .
Are you full or half?

 

[rick3452]

Half system
thanks

 

[Bt Doctur]

then the 2 slot ones are what you need

 

[rick3452]

Thanks BT. He’s adamant about the four sides....