[Medicone]

At least for the 8.1L Captain's choice, it is my understanding that the spring side should be sticking out of the heat exchanger - not the pointed side.  The spring is in contact with the hot engine coolant.  When the engine coolant gets too hot, the spring is biased away from the heat exchanger which causes the bypass tube from the thermostat housing to be blocked so that ALL of the engine coolant flows from the engine into the heat exchanger for cooling.  Also, the thermostat usually has markings on one side that say "to rad" (e.g., to radiator).  If the spring were inside the heat exchanger, while it still would probably work, you may get a slower reaction because the temperature of the coolant in the heat exchanger should be lower than the temperature of the coolant coming from the engine (e.g., outside of the heat exchanger).  Also, I'm not sure about the length of the spring extension (minimal), you would want to avoid having the spring extend into the heat exchanger and damage the tubes therein.

The parts manual and user manual shows the thermostat in the correct orientation (e.g., spring side up).

Also, Page 83 of the Parts Manual shows how the thermostat works within the thermostat housing during warm up, normal operation and overheat.  You should definitely look at the Page 83 as well as the water flow diagrams.

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Best of luck!

-M1