I am trying to remember/figure out as my new long block goes in about the two "screw" in ports on the heads. The drivers side is in the front and the passenger side is in the back. Is the front the temperature sensor and the back a freeze plug?

Anyone have any pictures; this is only visible once the lower intake manifold is removed.

 

the one on the front driver's side is the cylinder head temperature sensor.
the one on the back passenger side is the knock sensor - it is disabled in the pcm, but still installed. it is a donut looking sensor with a bolt that goes through it to hold it on.

 

The knock sensor goes in the center of the valley between the banks, on a round machined pad with the threaded hole in the center. This pad is just behind the front 'wall' and water pump housing in the photo below - the masking tape is still in place, so you can's see the threaded hole.



In this pic, are the holes you're asking about the one around 1/4 of the way down the head on the 'wall' of the head facing the center valley? The driver's side is blocked from view by the coolant passage on the head and the passenger is below the intake runners, visually between the 3rd and 4th port (it's actually right below the last runner). If so, these holes are blind and do not penetrate into an oil galley or coolant passage. The passenger side (to the rear) is empty and the driver side (to the front) contains the temp sensor.

Herb

 

Alright well; how does the temp sensor work if they holes are blind? Radiant heat? I never thought to see if they were blind holes; maybe this will save me some grief.

 

I guess the aluminum transfers the heat well enough to not risk the chance for a leak in that location? The actual sensor 'bulb' looks like a normal immersion type coolant sensor.

Herb

 

Yeah; strange indead. O well; saved me some time and grief running down a plug this morning

 

I did the same thing - I looked for the "missing" plug for an hour before I stuck a small screwdriver into the hole and found it to be blind.

Herb

 

i did the same damn thing, these motors will drive you nuts with stuff like that

 

the sensor bottoms out on to the head and the aluminum just transfers the heat. atleast that is what sal told me, i asked the same question