Does anyone know what size the coolant temp sending unit is?

I want to add an idiot light to my CMC race car for water temp, and I need to know what size sending unit to buy.

The choices are: 1/2" NPT or 3/8" NPT

 

3/8 Npt

 

Thanks....This is for the passenger side head correct?

James

 

Yes and actually the one in the water pump has the same threads.

 

Great... Thanks for the help.

 

You could use the driver's side head also, and retain any gage, etc that's in the passenger side head now.. it'll have a plug in the same spot as the psgr side head[both heads are the same..]