When I bought my heads they were bare, so I didn't realize I was missing a plug until just now. Both heads have a threaded hole for the coolant temp sensor, I bought a sensor and stuck it in the driver side head because I won't have room for it on the passenger side with the HVAC equipment over there. So now I'm trying to track down a plug for the other hole on the passenger side head. I know it's a metric thread, but not sure what size. If anyone has a part number that would be awesome.

Also, I had another question relating to the heads. If you look at this picture (passenger side head), you'll see the hole I was referring to directly to the left of the header flange. Then there is another small to the left of THAT. What is this other hole? Does that need to be plugged to? If so, part number for that as well please.

 

I'm going to go out on a limb and say if
That the hole is 12mm x1.5


You can also see in the pic i have nothing the other hole.