Need help locating an obsolete part

[kazoocruiser]

The truck is a 1981 C10 Scottsdale longbed with a 250 inline 6 with the integrated head.

The switch I need screws into the oil galley on the passenger side of the motor, about 4-6 inches to the right of the oil pressure switch.

It is a 2-port switch, which allows manifold vacuum to flow to the heater stove actuator, until oil temperature reaches 150 degrees F. It is called a EFE valve or switch.

The part number I pulled from the service manual is 866887. CORRECTION 366887 Thanks ElGracho.

Thanks in advance for the help.