Anyone running this shutoff valve?

[Steve Cole]

I don't know what it is called, but is there some type of shutoff valve that goes in line between the water pump and the heater core for non AC trucks? I am looking to be able to shut off the hot water that would normally circulate through the heater core in the summer. I don't need any additional radiant heat in the cab when it's 100 degrees outside.

What's it called and where can I get one?
Posted via Mobile Device