I have a 69 with a ZZ4 crate in it. I have just completed installation and wiring of the original console guages...Does anyone know if the CG-19 (original sending unit) will work in this crate motor? Thanks!

Yes

Great, I've got one due in from Rick's tomorrow! Thanks!

Actually Steps, unless he uses a adaptor, it will not fit into the head. I'm pretty sure it's too large. I had to mount it on top of the thermostat housing on this ZZ3.

http://i55.photobucket.com/albums/g136/Caman355/244-1.jpg

ZZ4 uses the smaller thread size too

http://i55.photobucket.com/albums/g136/Caman355/MVC-001F-44.jpg

I assumed he would have the common sense to fit an adaper if required
Rather than just dropping it in the hole, then when starts up water go every where.

Actually the problem he is going to run into is an original sending unit it too large for the ZZ4 head. He would need an adaptor to go from small to large and then he's moving the unit out further from the head. Not the best way to go. I'm sure he'll figure something out.

I will have the sending unit today and take a look at size difference tonight...any idea where to pick up an adaptor?
The only reason I am looking at installing the new unit is due to the fact that the existing one that came with the ZZ4 has a totally different type of connection on it, and even if I got that to work I'm not sure it would work with the OEM gauges?

2 problems with using a adaptor. 1 is it moves the sending unit further away from the head and more out of the flow. 2 is now your sending unit will probably hit your header. As you can see in the pic above, there is not much room. Maybe your situation might be different. If you want to try it, you can probably make one up at your local Ace hardware.
My ZZ4 didn't come with a sending unit so I don't know what comes in them now as far as working with an OEM gauge. You can see in the pic below, it just came with a brass plug.

http://i55.photobucket.com/albums/g136/Caman355/46.jpg

I'm having a similar issue. I just fired my ZZ/4 up for the first time this morning. I have a sending unit from a later engine that threads right into the hole on the drivers side cylinder head, but my center console guage doesn't work. I had my buddy disconnect the wire form the sending unit and re-connect while I watched the guage (engine warmed up) The needle barely deflected. I also checked voltage at the connector and read 7 volts hooked up and 9 volts disconnected. :confused: Before I installed it, I heated it up with a hair drier and it read approx 400 ohms hot, and watched the resistance drop as it cooled, so I thought i had a good sending unit, but I guess I need to figure something else out. BTW, don't unscrew the sending unit with the radiator filled! :o I just noticed this thread was from last August. has anyone found a solution??

The ZZ4 has plugs in each head, can you mount the sending unit on either side? The PO of the motor I bought had the sending unit in the passenger side head, can I assume I can just swap the plug and adapter.

I doubt that moving the sending unit outward with an adapter will have much effect on the temp reading. Hitting the header is another story.

If you're brave, you could drill and tap the head to the correct size thread for your original sending unit.

Nothing wrong with using the pass side head for the sending unit. "Might" read a touch higher than the driver's side though.