Elbow gasket. Open, closed or restricted water flow gasket?

[Tmakaro]

I am in the process of replacing my exhaust manifolds and elbows on my mercruiser 4.3
The engine has a dry joint system that was originally raw water cooled. A long time ago I converted it to a closed cooling system for the engine block. manifolds and elbows are still raw water cooled.
so after pulling everything apart, I see the gasket is an open flow gasket. The manual says to use a restricted flow gasket. Which one should I be using?

 

[Pmt133]

Open flow for closed cooling block with raw water exhaust.

 

[Scott06]

I am in the process of replacing my exhaust manifolds and elbows on my mercruiser 4.3
The engine has a dry joint system that was originally raw water cooled. A long time ago I converted it to a closed cooling system for the engine block. manifolds and elbows are still raw water cooled.
so after pulling everything apart, I see the gasket is an open flow gasket. The manual says to use a restricted flow gasket. Which one should I be using?

If the raw water exhaust worked after conversion to half system replace with the same

 

[Fun Times]

Dry Joint Exhaust – How to Position the Restrictor vs Full Flow Gasket | PerfProTech.com

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