What is this thing?

[franknitticutlass]

What is the thing that screws in the block and is located between the #1 and #3 cylinders. right above the #3 spark plug. I used a few of your pics from the gallery.

 

[franknitticutlass]

 

[81Regal]

Temp sending unit for the dash.

 

[franknitticutlass]

Is it possible I can hook this up 2 a threaded temp sender for electric fans?

 

[anakputa]

If you have a controller for the fans..

 

[megaladon6]

i'm using that port for my fan controller and the intake port for my gauge.