Thermostat decision

[halemorg]

I have two 220 crusaders with closed loop cooling.
What temperature thermostat should I need.
I run my boat in the summer only in the Atlantic ocean, I am from Halifax Canada

 

[makomark]

160 deg F was the factory provided t-stats; using 170 deg F stats would help economy a bit and shouldn't have any adverse impact assuming the HX is clean.