water temp sensor
 

Im mounting my water temperature sensor on to my block and I don't have the flat spot to drill and tap on my block but I do have a metal neck where there is a sensor already there. I'm assuming I can but I want to make sure if its ok it I just mount it on the waterfill neck. I added pictures so you can see what I was talking about

The first picture illustrates where the Fan Thermoswitch is located at on the water pump housing's upper neck. My advice is to use the stock location on the BACK of the water pump housing. There's nothing wrong with it, it needs no drill/tapping to work and doesn't pose an interference concern with the accessory belts. See Aaron Cake's 1976 Cosmo thread for more information on this. He drilled & tapped the stock spot to accommodate a 3/8 NPT GM sensor.

What Coolant Temp sensor are you using? The 'Squirt can accept just about any sensor, but I think you'd best be served by a stock FC/FD one or a LS2 Corvette one as both use the same M12x1.5 threads that the pump housing has for a no-fuss fit. I'm using the vette one as the matching connector is easily found at any Autozone too. Same scale as the one Aaron Cake used, just in a more convenient package that threads right into an unmodded housing and can be found anywhere for cheap too. Mine was $7 at Advance Auto.

I bought the gm 3/8 npt gm sensor. I have the entire write up printed out and I just assumed it was drilled and tapped in the front for a reason but if i can ill just go ahead and use the stock location.

To use the 3/8 NPT GM Sensor as Aaron Cake did, you'll still have to drill and tap the stock location for 3/8 NPT threads as he did with the Cosmo. Seems kinda silly to reinvent the wheel like this when a 2004 Corvette Coolant Temp Sensor has identical specs, but has the same M12x1.5 threads like the stock sensor does. Same connector as the 3/8 NPT one too.

My Advice: Get a LS2 Corvette sensor, put it in the stock spot, have a cold one as a reward for saving yourself the time/effort from drilling/tapping and get on with wiring the squirt up. There are much larger issues you'll encounter, so using a stock part in a new application isn't cheating :lol:

thanks. I didnt know i could use a stock sensor i still have the sensor there i may just go ahead and use it just have to get a new pig tail

The pigtail/connector seems to be a trouble spot as I've not been able to locate who manufactures it as of yet. And since I could not find one in suitable condition, that is what made me go with the Corvette sensor instead. A sensor is no good if you can't connect it.

Rock Auto lists the Sensor here:
Sensor: ACDELCO Part # 2134514 for $7.34 (GM# 19236568)
Connector: STANDARD MOTOR PRODUCTS Part # HP3840 for $5.80 (GM# PT169)

Any parts store can cross-reference them to get you what you need locally.