What is this plug for and where can I get it?

[MOPARENT]

Missing on my 440, a quick search thru the net gives me nothing, so here I am to call on my super-talented brothers and sista's that know way more than me......What is this plug and where can 1 get one?.....SEE ARROW

 

[chtampa]

Those two plugs, one larger than the other are for heater hose nipples. The third is usually used for the temp sending unit if the plug on the front face of the water pump is not used.

 

[68gtxman]

It's just a blank off plug. Here is a 3/8” plug, so search for the right size. https://www.summitracing.com/parts/...RN-_JQhgjm-_EAYcBmzLegsdgsQkhmExoCIwYQAvD_BwE

 

[Shorthorse]

It's just a plug with NTP threads. You can get them at a hardware store or they are available from companies such as Earl's. If you're looking for OEM for a restoration, I can't help you there but I'm sure someone can. Also, like chtampa said there are ports on the water pump housing for heater hoses nipples. That would be a different NTP type fitting.
Earl's, they come in different colors -